Sometimes if you migrate with truffle to a consortium blockchain network, especially if the network does not use proof of work, like at quorum, the migration hangs at the first transaction. Despite, if you check manually on the network with geth, the first contract seems to be deployed without errors, it is just somehow truffle does not get the feedback on that. Surprisingly, if you use the -- verbose-rp parameter, the migration continues without error. Do not ask why :)
truffle migrate --network quorum --verbose-rp
