I have the same issue, once the error comes up the only way to quit is to force quit.
This error persists even though the ODBC connection is re-established.
I have confirmed this by going to the system DSN and clicking on "Test" and get "connection is successful". So it seems like once FMP loses the connection it does not retry.
There is also an option in the driver "Enable automatic reconnect" but this makes no difference because it's FMP that's not reconnecting to the driver.
I see thst this error was also reported in version 10 so it doesn't look like any effort has been put into fixing it. A bit of a shame I was hoping to avoid creating mirror tables and all the syncing issues that go along with that.
At the very least you should be able to close your files without force quitting.
- MS SQL Server 2008, Windows Server 2008 Std.
- FMP 12 Advanced 12.0v2