+ .. warning:: When upgrading MySQL database you can encounter issue with

+        incompatible columns. In this case try to check the collation of the

+        mentioned column by ``show full columns from <table>;`` in ``mysql``.

+        If the collation is something else then `utf8` you need to convert

+        your database to `utf8` first. See

+        `this guide <https://stackoverflow.com/questions/1294117/how-to-change-collation-of-database-table-column>`_

+        for how to do it or if you have SQL script for db setup,

+        you can change it directly in the script.