Your screenshot has a too low resolution and is unreadable.
I gess I read in French..: "une erreur interne s'est produite: a???????? it must be a number or string"
Translated: " an error occurred: a???????? it must be a number or string"
After search I think the message is:
"An internal error has occured: AgStoreProviderSession:getEntityByID: id must be a number or string?"
yes this is the message I got, but in french . any idea about the reason?
Sorry next time I will write it down.
About the catalogue have you try to optimize your catalogue?
In Files/Optimize. ,en français menu Fichier/Optimiser le catalogue.
yes, I usually do it at least one time per day when closing LR.
Now, I just discover also that I had many pictures with zone which are marked as face but are not at all!!
It seems that I have some cleaning to do but no idea how it happens.
Thanks, I look at it, very similar to a tutorial that I found in a magazine. I did exactly what she mentioned, and it worked perfectly then suddenly I got the problem.