Error 500 - mysql connection

[Follower19]

Hello 

When I tried to update forum to new IPS - I have an error 500. I decided to restore my site from last backup, but error isn't disappeared.

I have a logs... http://pastebin.com/mYbCNNr1

but I don't understand how to solve that... Maybe problem with my old database? How to check it for any issues? 

Server info: ubuntu 15, vestaCP

[Volvospeed]

Could be a ton of things. I would check error log. In my experience with 4.2.x upgrades this is usually caused by a plug in that needs disabled. Login to the ACP and try disabling any third party plugins. If you cannot get to ACP you can do it from phpmysql.

[TheSonic]

Whats your old versionnumber and to which version did you try to update?

Did the Upgrader start or when did this error happen (which step) ?

[Dean_]

Restore backup, disable all the hooks/plugins and delete all the themes except the default. As some have said it could be a number of things but mine turned out to be the theme causing issues along with navigation icons as a hook.

Best of luck.

[Follower19]

I don't have access to my ACP.

Forum have default theme. 

How to disable plugins from phpmyadmin?

[icedream]

Seems that your database is down, you should check if your database is online, and restart it if offline.

[Volvospeed]

Not sure how you manage server but if in doubt a service restart will not hurt. Depending on OS you run something like:

service mysqld stop

 service mysqld restart

Once dB is back up you can look for the table with widgets and plugins. I will look up exact tables when I get back to my desk. Have you tried going to path/admin/upgrade?

Really could be a ton of things. Check the error log and assure that all your services are running.