Has anyone seen this error before in SHOUTcast? Seems the YP is not picking up this server because of this?

WARN   [YP sid=1] response returned 500, NOK

I checked with the SHOUTcast forums and while the warning came up a few times, they were no replies to the questions.

Tickets to SHOUTcast go unanswered etc.

Any help is appreciated.

a few question for you so I can help you find the solution.
did you set-up an account with https://radiomanager.shoutcast.com/
that is the first step, second add a station and get an: Radio GUID and Authhash
that number gets inserted in CentovaCast YP Listing page

if you need more help ask and I'll try to answer