Hi Camu,
Once again, thank you for the help!
I deactivated all plugins, and changed the active theme to the same one that works with another Site. Reactivated the plugin and the error code changed to 215 Database not ready.
So before I do something wrong… I would like to check if this is too obvious, if it rings a bell… So, please, would you have any other advise?
best regards,
Rogerio
Thank you, Camu! Much appreciated your help. I will try to isolate those two hypothesis.
Once again, thank you so much for your help.