Hello,
I reached to the last step to restart QT wallet to activate masternode, but I received the error message: Invalid port in the masternode.conf, port must be 9399 for mainnet, and the wallet cannot be opened. I changed the port to 9399 as requirement, but the result when I restarted the wallet still like that. I do not know how to fix this error because everything seems to be all right. Please help me ! Thanks.

https://s22.postimg.org/5f3fusku5/Screen_Shot.jpg