Two Domain names
 

how do I deal with two domain names
one works and the other you can not log in
I get this error
In order to accept POST request originating from this domain, the admin must add this domain to the whitelist.

If you go to AdminCp> vBulletin options> General Settings> Post Referrer Whitelist

add the second domain there and it should work fine.

thanks
Do you know of any harm of doing this
such as license or search engine effects

I'm not sure at all about that tbh. I've never used 2 domains.

Yes, I used to run on multiple domains so my advise to you is just redirect the other domains to your main one or else you'll be terribly ranked in search engines especially Google. It's not even a good idea to park and use multiple domains on a site.

take snake's advice from above. doing whitelisting can put up a risk

Whitelisting isn't really a risk as long as you only add your own domains.