Crash serwera Sinatry

Cześć, zainstalowałem gemy: sinatra oraz sinatra-contrib(aby używać reloadera). Gdy uruchamiam serwer wszystko działa poprawnie, natomiast gdy chcę zapisać plik ponownie i odświeżyć stronę, pojawia się to:

https://iv.pl/images/72827564249819068999.png

A to logi serwera:

- Gracefully stopping, waiting for requests to finish
=== puma shutdown: 2018-07-07 13:02:08 +0200 ===
- Goodbye!
== Sinatra has ended his set (crowd applauds)
== Sinatra (v2.0.3) has taken the stage on 4567 for development with backup from Puma
Puma starting in single mode...
* Version 3.11.4 (ruby 2.5.1-p57), codename: Love Song
* Min threads: 0, max threads: 16
* Environment: development
* Listening on tcp://localhost:4567
Use Ctrl-C to stop
127.0.0.1 - - [07/Jul/2018:13:02:22 +0200] "GET / HTTP/1.1" 200 12 0.0040
127.0.0.1 - - [07/Jul/2018:13:02:22 +0200] "GET /favicon.ico HTTP/1.1" 404 469 0.0006
127.0.0.1 - - [07/Jul/2018:13:02:22 +0200] "GET /favicon.ico HTTP/1.1" 404 469 0.0005
2018-07-07 13:02:27 - LoadError - cannot load such file -- /home/dawid/Desktop/Learning/Ruby/Learn ruby/sinatra/index.erb:
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:122:in `require'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:122:in `require'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:249:in `block in perform'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:245:in `each'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:245:in `perform'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:236:in `block (2 levels) in registered'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:236:in `synchronize'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:236:in `block in registered'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1635:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1635:in `block in compile!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1040:in `block in process_route'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1038:in `catch'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1038:in `process_route'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:983:in `block in filter!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:983:in `each'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:983:in `filter!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1096:in `block in dispatch!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `block in invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `catch'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1094:in `dispatch!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:924:in `block in call!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `block in invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `catch'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:924:in `call!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:913:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/xss_header.rb:18:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/path_traversal.rb:16:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/json_csrf.rb:26:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/base.rb:50:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/base.rb:50:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/frame_options.rb:31:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/logger.rb:15:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/common_logger.rb:33:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:231:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:224:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/head.rb:12:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/method_override.rb:22:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/show_exceptions.rb:22:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:194:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1958:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1502:in `block in call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1729:in `synchronize'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1502:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/configuration.rb:225:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/server.rb:632:in `handle_request'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/server.rb:446:in `process_client'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/server.rb:306:in `block in run'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/thread_pool.rb:120:in `block in spawn_thread'
2018-07-07 13:02:27 - LoadError - cannot load such file -- /home/dawid/Desktop/Learning/Ruby/Learn ruby/sinatra/index.erb:
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:122:in `require'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:122:in `require'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:249:in `block in perform'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:245:in `each'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:245:in `perform'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:236:in `block (2 levels) in registered'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:236:in `synchronize'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:236:in `block in registered'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1635:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1635:in `block in compile!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1040:in `block in process_route'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1038:in `catch'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1038:in `process_route'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:983:in `block in filter!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:983:in `each'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:983:in `filter!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1096:in `block in dispatch!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `block in invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `catch'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1094:in `dispatch!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:924:in `block in call!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `block in invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `catch'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:924:in `call!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:913:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/xss_header.rb:18:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/path_traversal.rb:16:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/json_csrf.rb:26:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/base.rb:50:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/base.rb:50:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/frame_options.rb:31:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/logger.rb:15:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/common_logger.rb:33:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:231:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:224:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/head.rb:12:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/method_override.rb:22:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/show_exceptions.rb:22:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:194:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1958:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1502:in `block in call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1729:in `synchronize'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1502:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/configuration.rb:225:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/server.rb:632:in `handle_request'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/server.rb:446:in `process_client'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/server.rb:306:in `block in run'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/thread_pool.rb:120:in `block in spawn_thread'
2018-07-07 13:02:28 - LoadError - cannot load such file -- /home/dawid/Desktop/Learning/Ruby/Learn ruby/sinatra/index.erb:
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:122:in `require'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:122:in `require'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:249:in `block in perform'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:245:in `each'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:245:in `perform'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:236:in `block (2 levels) in registered'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:236:in `synchronize'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:236:in `block in registered'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1635:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1635:in `block in compile!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1040:in `block in process_route'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1038:in `catch'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1038:in `process_route'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:983:in `block in filter!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:983:in `each'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:983:in `filter!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1096:in `block in dispatch!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `block in invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `catch'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1094:in `dispatch!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:924:in `block in call!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `block in invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `catch'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:924:in `call!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:913:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/xss_header.rb:18:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/path_traversal.rb:16:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/json_csrf.rb:26:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/base.rb:50:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/base.rb:50:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/frame_options.rb:31:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/logger.rb:15:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/common_logger.rb:33:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:231:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:224:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/head.rb:12:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/method_override.rb:22:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/show_exceptions.rb:22:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:194:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1958:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1502:in `block in call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1729:in `synchronize'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1502:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/configuration.rb:225:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/server.rb:632:in `handle_request'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/server.rb:446:in `process_client'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/server.rb:306:in `block in run'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/thread_pool.rb:120:in `block in spawn_thread'
2018-07-07 13:02:28 - LoadError - cannot load such file -- /home/dawid/Desktop/Learning/Ruby/Learn ruby/sinatra/index.erb:
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:122:in `require'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/site_ruby/2.5.0/rubygems/core_ext/kernel_require.rb:122:in `require'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:249:in `block in perform'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:245:in `each'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:245:in `perform'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:236:in `block (2 levels) in registered'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:236:in `synchronize'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-contrib-2.0.3/lib/sinatra/reloader.rb:236:in `block in registered'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1635:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1635:in `block in compile!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1040:in `block in process_route'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1038:in `catch'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1038:in `process_route'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:983:in `block in filter!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:983:in `each'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:983:in `filter!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1096:in `block in dispatch!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `block in invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `catch'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1094:in `dispatch!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:924:in `block in call!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `block in invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `catch'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1076:in `invoke'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:924:in `call!'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:913:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/xss_header.rb:18:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/path_traversal.rb:16:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/json_csrf.rb:26:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/base.rb:50:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/base.rb:50:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-protection-2.0.3/lib/rack/protection/frame_options.rb:31:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/logger.rb:15:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/common_logger.rb:33:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:231:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:224:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/head.rb:12:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/rack-2.0.5/lib/rack/method_override.rb:22:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/show_exceptions.rb:22:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:194:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1958:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1502:in `block in call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1729:in `synchronize'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/sinatra-2.0.3/lib/sinatra/base.rb:1502:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/configuration.rb:225:in `call'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/server.rb:632:in `handle_request'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/server.rb:446:in `process_client'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/server.rb:306:in `block in run'
	/home/dawid/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/puma-3.11.4/lib/puma/thread_pool.rb:120:in `block in spawn_thread'

Dzieje się tylko gdy zapiszę zmianę i odświeżę stronę. Co zrobić?

Masz dokładne info w logach

2018-07-07 13:02:27 - LoadError - cannot load such file – /home/dawid/Desktop/Learning/Ruby/Learn ruby/sinatra/index.erb:

Jeśli taki plik istnieje to zacząłbym od usunięcia spacji z nazwy katalogu projektu. Bardzo często jest to przyczyna tego typu problemów.