I just tried to open my app in the editing interface and got an error. The app simulator had the typical “could not open – contact the person who made the app” message, and the part of the editor with the red mark indicating the location of the error said something like “try restoring to a previous version of the app”. Fortunately, I didn’t follow that advice. Instead, I hit “reload” in my browser and that fixed whatever had gone wrong. I wish I had saved some screenshots, but I was too shocked at the prospect of having to do work over again to take any. “Restoring to a previous version” may be necessary in some contexts, but in comparison with reloading, it’s something of a quasi-nuclear option.
AppSheet staff: If you are aware of what causes this error message to be shown, please consider modifying it to suggest simpler troubleshooting steps (like reloading) before recommending restoration to a previous version.
I think I may have figured out what was happening. I have a “Settings” table with one row per view. In one view, I used a slider control with a MAX of 14 for a number in that view. In another row I had set up an action that wrote a number to the same number column that could be greater than 14. I found the problem last night because I got an “ACTION FAILED” error with a group action that included the one to write the larger number. All is well now but, for people like me on free accounts (without the debugging tools that paid accounts can use), debugging can be quite difficult. It would be nice if we could run some sort of checker to find conflicts like this. For the most part, AppSheet is pretty good about informing us about conflicts and points them out to us but in the sort of case I just described (and some others I’ve experienced by can’t recall clearly now) finding the source of a generic “ACTION FAILED” error in a group action (and on a free account) can be HARD. Sure would be nice to receive a more detailed account of WHICH action was failing.
At any rate, perhaps this conflict was causing a temporary issue when I tried to load the app and perhaps THAT was behind the “try restoring to a previous version” message. Since others don’t seem to be experiencing the same issue much (no one chimed in with “me too” here), I assume that the kind of “restore to previous version” sort of message that I got is fairly rare – only comes up when there are conflicts that the system doesn’t flag properly.