Because of this difficulty (anyone, please?) I am beginning to think that I need to re-install RW 8, having first deleted all my addons - or, better, saved them somewhere else.
In which case, does anyone know how to see at a glance which addons each of my projects uses, please?
Surely I don’t have to open each project, see the spurious error messages, and make a manual list… so that I can re-install only those I need?
TIA!
Good question. I would like to know an answer for this as well.
I’m kind of heading towards having to completely uninstall everything (I’ve been using RW since version 3!), launching each project in turn and only re-installing those (third party) add-ons which it complains about.
It is January after all; clean sweep.
Happy New Year!
I’ve now successfully (uninstalled, ‘purged’ and then) re-installed RW 8.7; and moved my add-ons one by one into the ~/Library/Group Containers folder as ‘Managed by RapidWeaver’.
The fact that I no longer get such messages as these does appear to suggest that there is some way in which RW retains a list of (non-existent) addons… now looking forward to getting back to work 
Thanks everyone!