Getting errors when trying to open Central Administration

Question

Our Public facing website developed on sp 2013.

 

unfortunately since morning we are unable to access Central Administration and Cross site publishing but Public facing website is working fine.

When trying to browse CA from the server it's showing following errors

"Loading this assembly would produce a different grant set from other instances. (Exception from HRESULT: 0x80131401)"

 

for more info please view the image

 

 

if anyone faced this problem or knows how to resolve it then kindly tell me, it's very urgent for me to resolve it so your help would be highly helpful to me.

Thanks in advance.