Posting server problem [Help!]

Howdy, ok so I am trying to post a server on PMC but it said this when a click save: To save, review/fix the following:
Failed to ping "-IP-". Make sure it is properly setup, port forwarded, online and other people can connect to it.
Note: Hamachi servers are not allowed but you can post them in this forum.

Now, when i tested for ownership, it could connect and all my friends can to...

Could someone/Mod please help me!