> I am sorry, I was never able replicate this bug.

It occurs with most of my large projects and never with small ones.

> If it is this regex that causes problems, it can be removed completely. It is used to enable clicking on error source and opening in in appropriate editor. Feature almost never used.

I don’t use the feature much at all, but I expect that is because I am quite familiar with Therion and usually have the culprit files open in a text editor already.

When I was a new user and had not figured out how to make use of external editors with Therion, I used the feature all the time.  I think it is worth fixing the bug, especially if Olly is on the right track.

Bruce