lof file rotation in webmin/virtualmin fails

the forced log file rotation (Logrotate version 3.7.8) fails in my virtualmin 4.17.gpl/webmin 1.750 setup on centos 6.6. It returns this:

Forcing the immediate rotation of all log files .. .. failed! See the output above for the reason why.

It only does not show the reason… :frowning:

Anyone with a clue?

I got same message every now and then when i manually force log rotation but the job is done even it reports with error. It would be nice if someone from Vmin can give any answer to this as i’m curious what could be the reason.