Error when adding Traffic Prioritization

I'm receiving the following error when trying to add Traffic Prioritization. Has anyone else received this error or can offer a solution?

Error: RPC error 'ERROR_UNKNOWN': bad argument #1 to 'len' (string expected, got nil) -> stack traceback: ?: in function <?:73> [C]: in function 'len' ?: in function '?' ?: in function 'decode' ?: in function <?:50> (tail call): ? ?: in function <?:324> [C]: in function 'xpcall' ?: in function 'try' ?: in function <?:290> [C]: in function 'run' ?: in function <?:345> [C]: in function 'xpcall' ?: in function 'try' ?: in function <?:261> (tail call): ? /dumaos/api/cli.lua:48: in function </dumaos/api/cli.lua:30> [C]: in function 'xpcall' /dumaos/api/cli.lua:59: in main chunk [C]: ?