DNS changed and now my Admin Control panel asks to re-create users and groups ...

DNS changed and now my Admin Control panel asks to re-create users and groups ...

Hi All, 

I changed my DNS provider, and now it does not seem as if all is well - it is asking for domain setup again. I can still login to my accounts, and mail seems to be there, but how do I safely complete setup without losing accounts/mail etc. ? 

Regards, Sam