Hello!
I noticed this yesterday evening while searching potential problems in the device manager of Windows. I confirm I have the same. In the device manager, I found 3 separate lines :
In line "Controlers audio,video & games" , device TONEX : In properties/events I have the same information you found and in the list of events, the last event is " device not started: IKMultimediaUsbAudio-TONEXks.
In line "Input Output Audio" i have devices (speaker Tonex, line Tonex, Microphone Tonex) but without any apparent issues
In line "IKMultimedia USB audio device"/TONEX I have also same error than previous about installation not completed...
So, I wrote already to support IK to explain the problem, hoping they will help because it seems we are only 2 in the world to have such issue