adding external host and getting "The external host is in the black list"

I have working app in backendless. And I have another one which I plan to use as copy for demo. While adding external hosts to second app, (same hosts as in first app) I got this error “The external host is in the black list.”
the host is “ac.cnstrc.com”, the appId is C127AD83-F790-6589-FFE6-3E58E09D6F00
original app id (where host is added properly) DECCC828-2720-F3EA-FFAD-586EEF9BD600

Could you please try adding it again?

Worked now, thanks!