Thanks @robb for translation!
I have another Christmas program today and can’t have look now but I’d copy the admin password from the DB of a working installation to the DB of the failed freepbx…and maybe check rights in /var/www/html/freepbx…
I could reproduce your case when I put the modules to “not selected” under admin access:
You could set it to access all modules again via mysql on command line:
echo "update ampusers SET sections = '*' where username = 'YOURADMINUSER';" | mysql asterisk