Thanks for FECT I found it very helpful. I have a few suggestions ... feel free to ignore ... you probably have better things to do in your evenings
In my case I was not looking for a conflict between extensions, but rather trying to see what was causing my bank to not display transaction listings.
I believe a frequent use will be for people to find if an extension is affecting "something" ... not necessarily another extension. So my first suggestion is to provide an option for FECT to allow the user to *not* select a target extension. I assume the target extension is never disabled so it can be tested with every iteration, and someone having trouble with a web site rather than an extension might go through 7 or eight iterations before realising (or never realising) that the extension they were forced to select was unluckily the one causing the problem. Perhaps the dropdown list could be labeled "Choose an extension to be enabled in every iteration", have a (default?) value of "none", and a help text of "If a particular extension is being interfered with, select it so that it is available to test on every iteration".
Also, I wonder if no-restart extensions could all be disabled (without restarting?) in the initial iteration to see if the problem is within them. If it is so, hopefully we could do the iterations without needing a restart with every iteration.
When I finally identified UAControl was my problem, it was disabled, but I had to restart and then everything was enabled again. So I had the disable it myself and restart. Maybe on the final "solved" iteration, if the problem extension is disabled can it just be left disabled and the session ended without restarting FF; or if the extension is not disabled could it be disabled, session ended, and FF restarted all in one go?
It could be that I used it wrongly or do not fully understand FECT, after all this was the first and only time I have used the tool.
Thanks again for your generosity.
Kind regards
Dale