Pex prefixes not working.

So when my friend and I got this new server. We used FileZilla (The FTP) to install plugins and stuff like that. We configured Pex and how we wanted it. It was working on the server that we have been running for over 5 years now and pretty copied the files over. But when we made the owner rank prefix and all of the other prefixes, They didnt work for some odd reason. I was wondering what is happening. It started to do that same exact thing on the server that we are running for over 5 years. It didnt do that yesterday but it is doing it today. I was wondering if someone could help me and my friend out. It will be really helpful. Thanks in advance -xCoolTy