You're right Birkett, I will try to find out how to fix it and post it here later. Maybe tommorow.

Let's see, Admin CP -> Maintenance -> Execute SQL Query, to run queries we first need to give ourself permission to run queries. To do this, we edit this section of config.php:
with x being our userid number (usualy-1).

Now, when you do this, you have permission, but I dont know what to choose, maybe option to set: Yes - Receive Private Messages, and when do this,
https://vborg.vbsupport.ru/external/2009/07/10.jpg
as the reset doesn't change anything.

You already have the option to receive messages. It's saving sent messages you want to change.
I'll look in my database to see where this is saved.

I know, but can't find it anywhere