Q I have been trying to use Remote Mouse with my Mac Pro and iPhone, but am plagued by error messages, and repeated entries in the logs about crashes whenever I try to click with it. There are also log warnings from Firewall[107], NetBarrier, and com.apple.usbmuxd. What is going wrong?

A Without understanding in full how Remote Mouse works, it is hard to suggest how to diagnose this problem. However mention of your software firewall and NetBarrier suggests one likely cause, that either or both of them are blocking incoming network packets. As Remote Mouse uses a WiFi connection to your Mac, any firewall or other block to incoming packets will stop it from working.

Before you try anything else, you should disable or remove all firewalls and other security software, falling back on the protection in your modem-router for the time being.

Several users have reported similar issues with Remote Mouse; if you wanted to get to the bottom of them, you would need to sniff network packets using a tool such as Wireshark, which is not a trivial task. If removing local network barriers does not solve the problem, your next recourse should be with the Remote Mouse support desk, as they will have a good idea as to how it works, and how to unravel such a problem.

Updated from the original, which was first published in MacUser volume 30 issue 6, 2014.