"Vaultmp.dll" and "can't connect" to server errors

[leozcm]

Hi,my friend downloaded the server files and client files in order to open a server. His server was in the list, but when i tried to join a "can't connect to server" error just popped.And he(my friend) can't join his server because an error pops too: "vaultmp.dll error".
please help us.:)
thank you very much.

[Volumed]

Reinstall the Server, and delete any old version server files if he got them.

And he should also clean hes own VaultMP client files for old versions.