AI2 Companion only working sporadically and Build/Save apk to my computer not working at all

Companion working sporadically. When Companion works, my app works as designed.

Build and save .apk to my laptop not working at all. Error message is "App Inventor is unable to compile the project. The compiler error output was ". The message does not say what the error was.

My app has 15 global variables initialized and 15 blocks. Is there perhaps a limit to the size of the app that can be compiled?

Try compiling a test project with just a button or label in it. does that work ?
If it does, then there is something in your project that needs attention.

Can you show your blocks ?