When I try to run this, nothing happens. My file is saved as .css and my syntax is set to css as well. The following console message is given:

Traceback (most recent call last):
File "/Applications/Sublime Text.app/Contents/MacOS/sublime_plugin.py", line 556, in run_
return self.run(edit)
File "/Users/LG/Library/Application Support/Sublime Text 3/Packages/CSScomb/CSScomb.py", line 18, in run
syntax = self.get_syntax()
File "/Users/LG/Library/Application Support/Sublime Text 3/Packages/CSScomb/CSScomb.py", line 79, in get_syntax
if self.is_scss():
File "/Users/LG/Library/Application Support/Sublime Text 3/Packages/CSScomb/CSScomb.py", line 112, in is_scss
return self.view.scope_name(0).startswith('source.scss') or self.view.file_name().endswith('.scss')
AttributeError: 'NoneType' object has no attribute 'endswith'

The weird thing is that it sometimes will work. I just haven't figured out when that is, yet.