Corrupt file build tool error?

Having a possible fatal problem - many build errors the last days for no reason I can think of, but upon rebuilding the entire project, I am getting this message

Severity Code Description Project File Line Suppression State
Error Unable to delete D:\000 UnrealProjects\Genius - 005\Intermediate\Build\Win64\GeniusEditor\Development (Unable to delete \?\D:\000 UnrealProjects\Genius - 005\Intermediate\Build\Win64\GeniusEditor\Development\Engine\SharedPCH.Engine.ShadowErrors.h) Genius D:\000 UnrealProjects\Genius - 005\Intermediate\ProjectFiles\UnrealBuildTool 1

I found the file and manually deleted it, but that destroyed my project, so I went to the last backup and am currently restoring yesterdays codeā€¦

but I still get this error, and many errors while rebuildingā€¦but if i just BUILD, I can compile and run.

Looks to me like something has got corrupted, but I have no idea, and not enough experience to understand this.