Thank you for your post.
What was the customer doing just prior to receiving this error? Do you have any scripts that open a window that does not get closed?
Turning on and off the iPad is not going to reset iOS. How often do you reboot the iPad?
What other applications are running?
Any other information you can provide may be helpful in narrowing down the possible cause.
Just prior to the event, my employee will be entering simple data in fields. Specifically, they will be inputting a timestamp.
With the ipads, I don't have specially named windows that open. The employee starts at a list of jobs for the day, click a button to go the next layout that show details of a job and then a 2nd button to the next layout to enter data for that job.
We don't regularly force close the ipads. They are turned off every night and employees generally close out any open apps to decrease drain on the battery.
Apps that are frequently open: Google Maps, Mail, Photos, apple maps, intrix and safari.
As a side note, in iOS6, we periodically experienced a slightly different issue but I am not sure if it's related: an employee would get the message that your modifications were not saved because you were disconnected from wifi/cell signal, would you like to revert. it was impossible to revert. You would get caught in circle and the only way out was to force it. I am fairly convinced this had to do with a fault in iOS6 wifi connection. If the wifi connection was severed, the ipad/FMGo would not always pickup that the cell signal was fine.
Are any files of the same filename copied to the iPad? The message might occur if a file is copied to replace a file that is open, so the links would be different. When the original file tries to update the new file, a similar message might occur. This would also account why rebooting FileMaker Go would work, as it would then have to reload the files (and hence, any new files).
Since the iPad users are connecting to FileMaker Server, also check to make sure all the relevant ports are open. See Knowledge Base Article #6427 for a listing of ports that need to be open.
Please continue to keep me updated with any progress.
We don't do any offline work. The only file that users connect to is through the Server. I've checked all the ports and they are open.
If it happens again, I'll update you.
Fortunately, it's intermittent.