ignat, i figured it out
problem with mine was some information in the database that capabilities.php was trying to retrieve. i wont go into the details of how i figured it out, but here was my solution:
in my wp_options table, i found the option with the name “wp_user_roles”. in that same row, it’s “option_value” field has a lot of code/characters starting with “a:5:{s:13:”administrator”……“
this text is supposed to be one long string of text, but when i moved the database over, it had broken the long string into several lines with breaks inbetween. this made capabilities.php unable to read the information properly. once i removed all the breaks, the site was back to normal.
i hope this helps ??