Here I am having an interesting problem. for all time never met a error when running RDP.
Failed to find file C:\\Windows\\system32\\mstsc.exe.MUI
The solution was simple...
When you start the remote desktop client mstsc.exe I get the following error message:
The system cannot find the file specified.
the command is mstsc.EXE.mui there is a mui in EN-EN, en and en-US folders. I updated mstsc to version 6.3.XXXX next KB2592687.
If you have another method or this did not help. I will be glad for more advice.