I've attempted to upgrade 3CX from v11 to 12RC. Followed instructions to backup database, uninstall v11, restarted machine, and launch 3CXPhoneSystem12.exe. Before I could click "Next", an error window pops up, stating "The specified port is in use: 5000", and terminates. I've looked at resource monitor and the results of netstat -o, and port 5000 is clearly not in use. Please help! OS is Windows Server 2012. I have attached the install log as well.