I had the same issue, the code worked in my dev environment, and as soon as I moved it to prod it didn't.
I found the issue to be the Telerik.OpenAccess.Config.dll missing from prod
In dev I had installed the Sitefinity Program Manager, and when I upgraded the project, it added a reference to that file, but it the reference was to where Sitefinity program manger was installed (check the hint path in the proj file). So when you try to run on Prod without that Sitefinity program manager installed it gave this error. I fixed the issue by copying that file to where all the dlls were copied, changed the reference to that location, set copy local true, so when I built it would copy the file to the bin directory and the project would run.
That took hours to track down, since there wasn't really any helpful error logging on the subject.
Hope that fixes your issue also.