Recurring problems with "Assembly not found. Please recompile."

I am working with a local game, obviously with in-game scripting enabled. I have been progressing well, but keep having inexplicable issues with compiling the script. Compiling indicates success, 'Exit and Remember' gets me out to the main interface. A quick test with the 'Run' button and the very first operation of initializing a debug LCD doesn't work. Switch to another block and back and the info area says "Assembly not found. Please recompile script." AGH!!

I first began fighting this...

Recurring problems with "Assembly not found. Please recompile."