Lately I have been getting "Bad Perimeter" error messages when updating a web page using NOF 2015. When I upload the same page again, the error doesn't appear.

In any case, the web page loads and updates fine. The error message appears in a small separate box which stays n the screen. Then when the "File transfer complete" box appears .. I click the Ok button and the "bad perimeter" box disappears. This happens on different websites I manage for my clients.

What is a bad perimeter?

Thanks in advance for any advise!