Cannot Save Blend File Says, "Cannot open file filename.blend@ for writing: Too many open files" Today I saw something in Blender I've never seen before. It says, "Cannot open file filename.blend@ for writing: Too many open files". 



Which I'm confused on. It's the only Blender project open. I pressed the close button on the window and it didn't close. I spent 2 hours trying to find a solution online and couldn't find anything. 

Does anyone know why this is and how to resolve it?

If anyone can help it'll be greatly appreciated.
So I had no choice but to force close Blender and lost hours of productive work because of this problem. 

I still have no idea as to how this problem even occurred but a good reminder to always save your work constantly. Otherwise, you'll lose hours of productive time.