Sorry, my English is bad, but i will try to explain what i mean.
I made EventReceiver on Developer PC on VisualStudio 2012 and it's work on my developer's SharePoint2013 Server.
I made WSP packgage, deployed it to Client's SharePoint 2013 Server, activated feature and get an Error.
Could not load type 'Microsoft.SharePoint.Administration.SPDiagnosticsService' from assembly 'Microsoft.SharePoint, Version=15.900.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c'.
How i understood it's SharePoint.Dll version is another, but i can't find this version and don't know where it's on clients server.