I have a GFCI breaker for my bathroom. I added an aditional outlet and now I do not have power. I checked voltage on the hot side and I have that but nothing on the common. The breaker is not tripped and I have tried to reset it but still no power. Additional with the breaker off I put an ohm meter to ground lead and common and had audible tone. Am I looking at a bad breaker?

Turn GFI Breaker off then back On,
You want to use a meter or voltage indicator, At GFI Breaker look for voltage on load side of breaker, then bath.
If you had a tone with a connection, between ground and neutral, it needs to be located, you could use your meter with breaker off and remove wires to new outlet and see if you lose the resistance between the neutral/ground. Staple, pinched between cover and box?