Internal Server Error / An exception occurred while executing a query: SQLSTATE[HY000]: General error: 2006 MySQL server has gone away

[sambilanet]

Ok, I thought so, a little bit, it is only the database.
Now as you have a backup please try to follow the instruction in one of the links, and please let me know.

Neither the directory 'mysqld nor the mysqld.sock' exist

I think you need to make sure that your database is correctly configured first. If you’re not entering a hostname or using “localhost” a socket is usually used to connect to the database. Please check-out the following information. A lot of more can be found by search for the mentioned error message

error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)' -- Missing /var/run/mysqld/mysqld.sock