I need to look into whether this is an issue on Windows 10. But this is definitely an issue on Windows 7 and 8.1.
Windows only uses the first 15 entries in the shell icon overlays section of the Windows Registry which is starting to get a bit crowded as more and more applications are used as shell extensions. Windows has it’s own set then if you have lots of shell extensions like Dropbox, OneDrive, Svn or Git and any other apps you’ll hit that limit quickly.
This can be solved really easily.
Open up regedit (Start -> Run -> regedit)
Then navigate to:
Ijust prepended a “z” onto the overlays I wanted to put at the bottom of the list.