I filed a Feedback case 54665, with a test app, that discusses how an error like this can arise in server error logs:
Can't use an undefined value as a symbol reference at Line 118
This has been verified by Xojo Feedback testers. I see this error frequently associated with the user getting an Internal Server Error 500 when they refresh their browser when they find the app is offline in their browser. Especially mobile phone users who left the app loaded in background while the phone display was asleep. So now my question, which I posted in that Feedback conversation:.
Can this be related to a Timeout event occurring just as a user hits the app? Say the 60-second Timeout countdown has started because no Sessions are detected. Further, say there's only a second remaining in that countdown. And now the user hits the app. Can't this cause a problem like this? Not enough time left to adequately respond to the user request?