I found a bug, when no tables list is loading in left panel after clicking the "plus" button at the database name.
How to reproduce? It is simple. Just create any amounts of tables in the specific DB, where at least one table have a commentary with the Russian language (sorry, not tested with any other languages but Russian and English). Voilà! No tables list in the left panel, the "plus" button show no tables tree.
Duplicate of https://sourceforge.net/p/phpmyadmin/bugs/3927/