|The sender software needs to use the network to transmit PC screen images to the receiver. Generally, the reason failed to do so is mainly because of "firewalls". Your Anti-virus or network security software would show a message to ask you if you allow the sender software to use the network. If you see such message, please allow it, or choose "add rule" to the firewall setting.
And here are the TCP and UDP ports MirrorOp would use: