Thanks, found they were all read only (must have got installed like that). I have manually copied some exiting filters that I can now amend.

Trying to save a new filter, I overtype <New Filter> with my own name and click OK, and get the error: Cannot save! Destination file is read-only! There is no problem updating topics, and I cannot find any seperate file that might contain filter definitions that could be set to read-only. I have mov...