[Darryl Ramm]

This is annoying. I think the source of the main problem is understood, I've discussed that with Avid. They might have made some improvements but it seems to be still happening. Now maybe you have a different problem. What exactly were you trying to do?

The main problem as far as I can tell is caused by an modsecurity like web application filter. Likely Akamai's Kona.

This problem will hit purely based on content (including maybe non-obvious or invisible characters (i.e. formatting)) in the post. You can force the error to happen by using "bad words" like say "/ b i n / s h" (without the spaces) that a security filter might reasonably look for. And you'll see the same exact error that I think folks here see at times. Test it for yourself by trying to include the bad words in a post.

Some odd combination of text characters will trip this off, and it might well be badly done character string matching across very long runs of text... which may be why breaking posts up into smaller posts helps bypass this for some posts.

All the past folklore about emptying browser caches, swapping browsers etc.... I expect you might as well sacrifice a goat. All that I suspect is happening there is folks try something and then retype or paste back in a message and in doing so make some very minor change to the text that now avoids the system tripping up doing whatever weird character string matching it's trying to do.

I am hoping Avid IT is collecting these messages as they fail, examining them and revising the Kona filters. I've made that suggestion and more. Not sure what IT staff have done. Jeffro may know more.