I have a few Kotlin classes that cannot be found (ie. all usages red and not findable with CTRL + N either). I assume it has an incremental cache or something somewhere to keep this editor information ready since I can fix it for a single file by renaming the file (outside of IDEA) and compiling but gradle clean, idea rebuild project does nothing to fix it.
Is there a button that clean everything related to the open project (and not some global action like "Invalidate Caches")