I used to backup my addressbook by issuing the following command:
zmmailbox -z -m myaccount getRestUrl \"/calendar?fmt=ics\"
and always worked.
Now I installed 6.0.8 64bit and that url isn't working anymore.

In difference from the previous install, I now have Zimbra listen to http but on port 81 and https.
So the first issue could be that it was generating the url as :80 instead of :81. But anyway, I now changed config to https only, so it should compose the url as https://myserver, but it's not!
Is there any further configuration I need to do?