ES to server Download Error

Dear all,

We have two server's (Redundant) server and 5 client configuration. We are using Wincc 7.0 SP2 and Simatic manager 5.5

I am trying to download (Changes only) from ES to Server but during download i am getting error as "An error occurred during delta download. Standby OS could not be loaded:" Please see attached log file which has generated after error.

What could be the reason..? Please help me to resolve this issue of download.

Due to this changes only download problem, Whatever changes i am doing in Engineering station that i am coping manually in server 1 & 2. Example, if i am creating new tag & graphics then same new tag i am creating & coping the graphics in server-1 & 2.

Thank you & Regards

Sacheen