APM RDP ERROR

i need help on urgent basis please if any one can ,i have configure RDP seesion on webtop and i did all required configration with access policy AD AUH and advanced resource assign i can access portal secussfuly but once i click on RDP icon i got this error to use this programe or computer , first logon on to the following website 10.5.6.8please note this the virtual server ip and i logon into arelady , any idea whats the issue