Would it be possible for you to enhance this error message with the server that is being tried? We get a number of these but then our RGS config loads. It would be immensely helpful if this error message (or even a log message before this error) that showed what was trying to be connected. There are no event logs that give us more information on the server either.
FYI – The SfB RGS application gets the same error but just lists it once.
