Error trapping for syntax error: quote in unquoted cell

I've read other posts on this topic, and I know the solution to the specific error may be permissions. I also get the point about generally doing checks prior to errors occurring - as one person said, traffic lights are better than ambulances, and that was also my philosophy when I was a professional programmer (many moons ago). However, for this app, it is intended to go straight in and read the previously-set google spreadsheet for convenience of use. I want to trap the error that can occur if something is wrong to give the user a chance to then go and change the file the app points to, for instance, but this error forces a close of the whole app when you have acknowledged it, thus preventing the user from going to the screen where they can point the app to a different google sheet.

So, how can this error be trapped to stop it blowing up the execution of the program?

If you are concerned about RunTime errors, you should try to prevent these errors rather than react to them. AppInventor does not handle errors correctly everywhere, and to fix this would require a lot of work and changing a lot of code. We don't have enough information what causes the error. I also remember that there was an extension that could detect errors that AppInventor does not support. Search the extensions directory.

"quote in unquoted cell"

usually arises from incorrect formatting or data in the spreadsheet, combined with the method used for calling the spreadsheet data down to the app, and then hoping to create an AI2 list with it.

You would need to debug in that order...