Many people do not know the terminology - the meanings - of hot lead, common, ground, etc. Dodgeman is right about the 'common' lead.
The common lead to many people means the wire that is attached to a common grounded bus that is inside the breaker box - the white wire. Do not connect the white common ground wire that comes from that breaker ground bus to the "commmon" terminal of the switch, because a switch must have all 'hot' wires attached to it that come from the black wire that comes from the power box.
A problem occurs when electricians use the white wire as a hot black wire and they don't tape or paint it black, you can't tell whether it is a hot wire or a common ground.
There are three basic wiring diagrams for 3-way switches: 1. fixture after switches 2. fixture between switches and 3. fixture before switches They are wired in different ways. And more using 4-way switches. Many of these use the white wires as hot black wires (and red wires.)
Use a voltage meter to check which wires are hot. If you are unsure of what you might be doing, you might take the safety of a professional electrician. You might luck out, and then again -