Duplicate files problem in MonoDevelop

I'm at Unity 5.6, and this problem has been going on since 4.3.

Sometimes, suddenly, MonoDevelop sees two copies of many files, and this is annoying because of this:


"Go to Declaration" instead of just going there, expands to two different, identical, choices.

Formerly I fixed this by going in the solution options and deleting the "Release" configuration, leaving only the "Debug" configuration.

This doesn't work anymore: I deleted the Debug configuration, restarted everything, still duplicate files.

Will anyone, after 2.5 years, FINALLY try to solve this problem?
I know it's obviously not top priority, but getting ZERO answers for so long is incredibly frustrating.

 

Unfortunately, in my 6 years of using Unity I've never run into this problem - that's probably why "after 2.5 years" you've been getting zero answers, because you're one of the only people experiencing the issue. Have you submitted a bug report to Unity, including your project in duplicate-file mode? That's probably the best thing to do to get it resolved. Another thing to try is to force Unity to recreate the Monodevelop project files - you can do this in modern Unity by deleting the current project files (just to make sure they are recreated) and then going to Assets->Open C# Project (it used to be "Sync Monodevelop").