I tried to share my Internet connection with another Mac but it failed. I could before I upgraded to Mountain Lion.
I have a 3G USB modem that I use for Internet. I went to System Preferences → Sharing → Internet Sharing → Select my 3G device from Share your connection from → Tick WI-FI → Setup WI-FI Options... and then enable Internet sharing.
However, the other Mac can see my network but cannot join.
How do I fix this?
HW: MacBook Pro Retina 15"
OS: Mountain Lion