Even though the file seemed Ok, it may be damaged. Check it by running a recover on it. If no problems are reported, test the recovered file just to make sure.
Best practice is to not use recovered files but to replace them with undamaged backups if this is at all possible.
This is no longer a problem with the database itself.
I did a recover on the file (no problems) and uploaded Eval Recovered.fp7 I was able to make ODBC queries on Eval Recovered.fp7 with no problem. So, I renamed it to Eval.fp7 (the name of the original file) and opened that on the server. It gives me the same error as above.
I'm coming to the conlcusion that the server will no longer serve ODBC data out of any file named Eval.fp7 but the exact same file named something else is functioning properly. There are ~80 people who use this database as a merge source for dozens of documents. I can't exactly change the name of the database.
Just speculating here. The error message referred to a damaged temporary file. I'm guessing that file may still be on the server and each file with a different file name would get a different temp file which might explain the issue. Finding and removing the temp file might solve this, but I am unsure how you would go about doing that.
You might be able to serve the file from a different directory on the server and that would at least get it back up and accessible to your users--though you might then have to update some external data source references in this file and others.
I didn't want to do it in the middle of the workday, but restarting the server seems to have corrected the problem.