Upgrading from 1.6.8 to 2.3.1 Site Error: Unable to Load Site Preferences; Invalid Preference Data

Hi, I have done this upgrade on a few sites but I am running into problems now. As usual I am following these instructions: https://docs.expressionengine.com/v2/installation/upgrade_from_1.x.html. The reason I am starting with 2.3.1 is because of Playa support, I understand that version 2.6 had big changes so I need to update to an earlier version first.

I have uploaded all files, restored file changes and verified file permissions and am trying to run the upgrade wizard when I get this error: Unable to Load Site Preferences; Invalid Preference Data

The thing is I seem to have connection to the database, if I willingly change the password to a wrong one in database.php I get another error: A Database Error Occurred Unable to select the specified database..

I am doing this on an old server that is currently running various versions of EE2 sites.

Any ideas on how to fix this?

Gylfi