[CentOS] /usr/sbin/httpd: symbol lookup error: /usr/sbin/httpd: undefined symbol: apr_array_ma+e

Damn!
Yesterday evening I leave my internal web server up and running.
This morning I experienced a down, so I did some quickly check and I saw 
that Apache is down.
Restarting I read this error message:

/usr/sbin/httpd: symbol lookup error: /usr/sbin/httpd: undefined symbol: 
apr_array_ma+e

What?!?
Why?!?!

Can someone telle me what happened?
I didn't touch this server, no new software install, no modified conf... :-(

Hope someone can help me.

Best regard, Nando
Chiacchiera con i tuoi amici in tempo reale! 
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