It seems that wlmscpfs received a C-FIND-CANCEL request from the modality, telling it to stop sending responses. So the server stops sending further responses and tells the modality with the given status that it understood the cancel request.
It is hard to say why the modality decided to send that message.
Maybe you can look into the modality log? Also, turn on debug mode in wlmscpfs (option -d) and see whether you find more details. It can also be a bug in wlmscpfs but that's not very likely.