The setup of Ethereum Mist worked like a charm (MacOS).
Then, I tried to connect to a test Network but the program crashed and continues to do so.

How can I fix this issue?

---

```
Node type: geth

Network: main

Platform: darwin (Architecure x64)

...eum/geth/ethash count=3
INFO [10-14|17:34:19] Disk storage enabled for ethash DAGs     dir=/Users/stefanschares/.ethash                      count=2
INFO [10-14|17:34:19] Initialising Ethereum protocol           versions="[63 62]" network=1
INFO [10-14|17:34:19] Loaded most recent local header          number=4362351 hash=188b4f…0c8c34 td=1174172911787544706344
INFO [10-14|17:34:19] Loaded most recent local full block      number=0       hash=d4e567…cb8fa3 td=17179869184
INFO [10-14|17:34:19] Loaded most recent local fast block      number=4362114 hash=d11d53…f16574 td=1173445059230676622547
INFO [10-14|17:34:19] Upgrading chain index                    type=bloombits percentage=0
INFO [10-14|17:34:19] Loaded local transaction journal         transactions=0 dropped=0
INFO [10-14|17:34:19] Regenerated local transaction journal    transactions=0 accounts=0
INFO [10-14|17:34:19] Starting P2P networking 
Fatal: Error starting protocol stack: listen udp :30303: bind: 
address already in use

```