If you get this error "Another device on the network is using your computer’s IP address" . It looks to be a problem with the DHCP server, which mistakenly assigns the same IP address to two devices. To fix this problem you can try to Renew DHCP Lease.
Click Advanced
- Make sure that you select the correct network on the left. In this exaple you are connected to the internet via WiFi
- Thank Click Advanced
Select TCP/IP
- Click on the TCP/IP Tab.
- Click Renew DHCP Lease ... wait about 10 seconds
- Click OK
This Shoud release you IP address and assign your mac a new one