"Script Handler Failed"

I have started to get the following “Script Handler Failed” error when using the clipping service from Mail to OF3.

Error executing handler script for <ScriptHandler:0x600000471950 com.omnigroup.OmniFocus.ScriptHandler.Mail NSBundle </Applications/OmniFocus.app/Contents/PlugIns/BuiltInClippingHandlers.plugin> (not yet loaded)>: Unable to convert the string “message:%3CDB7C0EE8.15786%peter.quinn@uwa.edu.au%3E” to a url. Make sure that the string is a valid URL, including quoting characters that aren't valid in URLs.

This is similar to other issues reported in these Forums but in those cases - at least the ones that I saw - it was related to MailTags. I have completely removed the MailSuite bundle (using AppCleaner & Uninstaller) so is is not that. And there is no reference to MT in the error - so this must clearly be an OF problem. This is a very recent problem

Not an OF user, but there could be some intersection between the reference to: quoting characters that aren't valid in URLs, and the fact that unparseable “smart” quotes do indeed appear around that message: url

(possible that they are introduced by the error messaging itself, but probably worth checking)

Update.
This is completely weird. I was focussed on the clipping service failing on a particular email. When I tried emails from different people, the service seems to work. It seems to fail with this error message with this one particular user. I haven’t tried everybody in my email, but I have tried about 5-10 different people and it works, apart from this one user…