[BUG] - IJ cannot resolve symbol [No Noob]

Hi,

I've been using Intellij Idea for the past two years now. Since at least a month, twice a day, my IDE suddenly cannot resolve symbol (Android/Java -> strings, layout, etc). I know it actually can resolve them, because when I hit "Ctrl + B", it goes to the "symbol" it apparently cannot resolve.

Yes, my projects still can be built.

Is it annoying ? Hell yeah !!

I've tried to specify a new SDK, invalidate cache/restart, re-build project, deleting .idea files from folder, etc etc. Still, it does that every now and then, and it's a MAJOR pain in the ass.

If anyone have a PERMANENT fix for this, I'll be grateful.

L.