SAP Business One 10.0 FP2208 - Failed to get access token, contact your administrator

Hi experts,

I am trying to get SAP Business One 10.0 FP2208 up. After server & client installation and when I try to login to SAP Business One (via both ip address & server name), I failed to login as I get the system message "Failed to get access token, contact your administrator". Kindly assist. It's urgent.