Getting InnoDb internal Errors on every query run
The problem is related with the internal representation of "timestamp" fields, probably caused by a bug in the database conversion procedure, occurred while upgrading from a previous version.

Exporting and importing the database "mysql" has fixed the problem in my debian server.

During the repair procedure, it's preferable to stop Apache and any other software that make use of the database, just in case.

Export the database:

mysqldump --events --quick --single-transaction mysql &gt; mysql-dump.sql


Import back immediately after the export:

mysql mysql &lt; mysql-dump.sql


Important: You must restart mysql service at this point to reload privileges.

service mysql restart


Of course I recommend to repair all your databases, because they could be affected.
You can do it one by one by hand, or all at once with a simple script:

mysqldump="mysqldump --events --quick --single-transaction"
exclude="information_schema|performance_schema"

cd /tmp

# Backup and re-import each database on the system
for db in $(mysql -e "show databases;" -s --skip-column-names | grep -vE "($exclude)")
do
        echo "Repairing database $db"
        $mysqldump $db &gt; $db.sql
        mysql $db &lt; $db.sql
done