SQLLite exception: Database busy

Hi

Hoping for another round of server help (fingers crossed)

About 15 minutes after an automatic restart, where everything worked well, I started getting this error message when logged into the game.
Logging out didn't help.

Restarting the server manually did.

It only happened this once, but it was the same day a player reported having been in-game for awhile doing things without seemingly getting them saved.
As in: The world was unaffected when he logged back in.
This can happen - for a short while - when you lose connection to the server, and it is still possible it was simply that. But it sounded longer lastning, he chopped down trees without getting logs etc. and now this.

I understand the error message, but do anyone know why this error occurs?
And what one can do to avoid it?

I was alone in-game when it occurred (and I think so was he).

Okay might have had a ftp client running trying to connect which I have now shut down. I wouldn't think that could do it, but since it hasn't happened before I am closing this one for now.
If the problem comes back I will reopen.

thanks for the help, that is good to know