I had the same issue on V5-6 R2012, I did found a trick,
first make sure your network card is active while no connection, there is a registery setting for that something related to media sense. So you can have the hardware id avialable while in network is not connected.
then, extract offline license,
start catia
wait a minite or so,
unplug your network cable,
then you will see catia window pop up.
now connect your network cable back.
working with catia, dont close it unless you have to.
repeate.