We have had a Form and List form working for over a year and do a weekly CSV Export through the interface. These were getting saved to the root /Portal/0/ folder. This has worked fine the entire year until today, when we get this error:

Error occurred: The extension '.csv' is not allowed. The file has not been added.

We had not altered any settings, have not changed file system permissions (and double checked them for full write access), and don't see anyone else with this same problem via Google search or on these forums. None of the Form and List settings indicate a problem.

The only other thing that seems like it might be a possibility is that last week's file was 491KB and this week's would have probably been over 500kB (+10-14KB/week). Is there a file size limit on Form and List CSV downloads; if so, can this be adjusted?