Accept invites to Customer Portal

Accept invites to Customer Portal

I think I have the customer Portal enabled and as a test I sent out an invite to myself (with a non Zoho user email) . I clicked on the accept invite - and rather than getting the screen to add my password I get an error message 

"Account access seems to be disabled. We request you to contact xxx@xxxxx.com"


Not sure what else to do. Please advise.

Thanks

Mel