PDO: Incorrect file format 'sources'

by cpunke, Saturday, May 03, 2014, 10:51 (3639 days ago)

Calling wget -q http://localhost/selfoss/Update every 15 minutes to update my feeds.

From one call to the next I see:
[Fri May 02 16:30:02 2014] [error] [client 127.0.0.1] PDO: Incorrect file format 'sources' in /var/www/apache2/error.log.

Same error after logging in to selfoss.

I changed nothing in my installation, the apache server runs and responds normla to other requests.
I changed the logger level to DEBUG, but nothing appeared in default.log

Anybody an idea ?