Omniturn error message 128 GT-75 G3 control

[jeffie_3]

Does anyone know what this is and how to fix it?

 

[FredC]

Error message #128?
If so, was the machine booting up, or running a program? I have no G3 controls, but some clues might help.
Seems like Omniturn is open on Thursdays, they have always been very helpful. Same with Richlin.