Couldn't save a file because it showed me that this file is opened somewhere else. So I go to the resource monitor to check for its handlers, but only explorer.exe showed in list. I restart explorer and get back to the code. For the first time..... for the first time in my life I hoped that this won't work. I press Ctrl+S, andddd, file was saved.

So, basically, windows's explorer can lock files. Nice job Microsoft. Nice job.