Could you tell me which version of Vmanager you are using?
Did you use the "search ip address" function in the options of Vmanager to have your CueCore2 displayed in Vmanager?
If not, could you add the ip address of your CueCore2 to this list and give it a try?
Last thing, could you send me the backup you succeeded to do locally, to let us check what could be the cause?
You can send it to support"at"visualproductions"dot"nl