Android Studio shows every line of code with lint -compile- error

Question

What the heck. My app worked yesterday. Today, every line of code has a lint error, including my imports. Mostly "cannot resolve ...."

cannot resolve symbol TextView
cannot resolve symbol Intent
...
...

Weirdly, I can still run my program to an emulator and it seemingly works fine.
This is what I tried.

• Cleaning project

• Rebuilding project

• Syncing project

• Updating Android Studio

• Restating Android studio

• Closing project and reopening

Update:
i have this note in my layout preview

NOTE: This project contains Java compilation errors, which can cause rendering failures for custom views. Fix compilation problems first.

I really don't know how to start trouble shooting this issue

Update 2 I am dying here. I reinstalled both Java and Android Studio. I believe I have the path for JDK and SDK correct. I tried a new project... wouldn't compile.. same thing. I appreciate any advice.

SOLUTION YEAH !!

"File" -> "Invalidate Caches...", and select "Invalidate and Restart"

Answer 1

I figured it out. Whew!

"File" -> "Invalidate Caches...", and select "Invalidate and Restart"