Error " Unable to manage service by DNSMNG "

I'm anewbi with PLESK,

My All sites hosted on PLESK server are down and also I can't setup NEW hosting acounts on PLESK. Always getting some error "DNS Server (Plesk DNS Server)"

I have tried several times to Re-Start it and always showing some error "Unable to manage service by DNSMNG "

So what shold I do?...

The same problem happens the second time. Anybody know the exact reason for this. My ALL sites are down due to this problem.

Anybody please help me.

Albert SP