The first thing I would do is login to the ubb control panel.
Check your os versions on the first page to make sure you have the same server software.
Then I would check the groups to see that they are intact.
Including the permissions for each group.
Then using your log for reference check each user in member management to see that they are in the correct group and everything else looks correct..
Just check don't edit yet. So you can research a comon pattern to what may be wrong.
As far as waxman you can have different login name from display name. Mine is different here.
It could be a corrupted table as stated by Phillip but I would make a backup of the complete database before mucking with it.
You can run it from the database section in the ubb control panel.
What I find a little odd is the last line of your errors.
You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ')
That could mean a corrupted script???? I would at least check the includes/config.inc.php file to see it is hosed.
