Why does Xcode save my files in autosave information?

I ran into this problem today while writing code. Whenever I open a source file in Xcode, make changes and save them, the file will be copied to the "autosave information" folder and the references in the source tree view (command + 1) are changed to the new location. Right now I cannot edit files "in place" but have to edit them and copy them back from "autosave information". The code files are in a folder within "Shared" (my local "GitHub" repository folder to be exact). The account I'm using to edit the files owns them and has r/w-permissions. On another account which doesn't own the files but has r/w-permissions the problem doesn't occur. My Mac is a MacBook Pro Retina 15" 2014, 2,2 Ghz i7 running OS X 10.10.5. Does anybody have an idea what's wrong and how to fix it? --- **UPDATE** So, I found out two things 1. it happens with files outside of the "GitHub" folder in "Shared" as well 2. it only happens if I open a window in XCode and add files (the file I open first is saved in place, the added files are saved in "Autosave Information") Removing ACL permissions didn't help.