Problem getting "Unmangle Microsoft ATP Safelinks" to work

I was pleased to discover this Add-on because I really dislike the Microsoft ATP mangled links for the reasons Peter Havekes gives in the documentation as well as their general ugliness in non-html encoded emails.

After initially installing it and restarting TB a couple of times it worked nicely. Now, it no longer does so. No other changes have been made. It remains enabled under Tools --> Add-Ons --> Extensions but emails all display with with the mangled URLs.

I have no experience of debugging add-ons but did look at the information at Tools --> Developer Tools --> Debug Add-Ons and recorded the logs there. There are a number of errors and lower serverity diagnostics. Including them here but AFAICT they don’t related to this Add-on.

I have tried reinstalling it a couple more times but w/o effect.

I would really like to get it working again. Can anyone advise?

Thanks
Tom Crane

My details:
Thunderbird version: 78.11.0 (64-bit)
OS: Slackware64-Current Linux (a little out of date w.r.t. updates BTW)
Unmangle Microsoft ATP Safelink version: 3.0.1

On


the autor provides a support e-mail - maybe you should contact the author directly.