Get Error detected message when try to authorize Kobo reader on Adobe 4.5 "Activation error code digital editions encounter an error on the activation server" Have a MAC, tried to deauthorize Adobe by control-shift-D. Won"t let me reauthorize, says

Get error message "an error has been detected activation error code digital editions encounter an error on the activation server" when I try to authorize by Kobo reader  on Adober 4.5.  on IMac

Tried reauthorizing Adobe but get error message "Try again later'

Pls. advise.  Tom