Not supported Server

So, im trying to re-setup my old server, it was a really good private server, a lot of bug fixes, custom itens and bosses and, im trying to setup it, i got an error and solved it myself but i got another error in my pserver that i can't join nexus, it keeps loading and in server.exe it appears:

[19:21:06] Not supported server detected:
Host: 25.84.87.34
Port: 2050

I need help!

Have you tried changing ports?

yes i did, but it didn't worked.