If a dialog appears containing “Invalid Class String”, with the error code “CO_E_CLASSSTRING“, followed by RxUniverse crashing, you must run C:\rxuniverse\run8\marshal.exe /RegServer in an Administrator command prompt.
To run a command prompt as administrator, hit the Windows Key, search “cmd”. Right click on “Command Prompt” in the search results and click “Run as Administrator”.
Note that this must be run each Thin Client workstation folder as well (C:\RxUniverse-Workstation)