I am also having this issue on OS X 10.11.1 -- I installed the newest XAMPP (5.6) release because of issues with MariaDB/MySQL when adding a user to a database in version 5.5 (the previous release before this most up to date version recently released). On version 5.5, there were syntax bugs with adding users so I upgraded to 5.6 only to find this more serious issue.
I have installed version 5.6 two times, the last time I cleared cache in my browsers and tried to add a database in PHPmyAdmin after making no configuration changes or tweaks to the base XAMPP install. This most recent attempt to install it, I left MySQL without a root user password to avoid making any configuration changes. I can't seem to find any information on the internet about resolving this specific issue. At this time, no databases can be added -- trying to access any of the stock databases on PHPmyadmin, including "test" results in the same error message: #1932 - Table 'phpmyadmin.pma__column_info' doesn't exist in engine.
If I add a database, I also get the same #1932 message. The database does not show up, but the next time I log in it is listed among the databases on the left-hand pane. After it is clicked, however, a "loading..." message comes up and it never loads.
This is with PHP 22.214.171.124 and MariaDB 10.1.8 . The 5.5.3 release, which I was also running on 10.11.1, was allowing database access normally.
Thanks in advance for any help