When starting to configure a new ASA 5500-x platform running 8.6(1) code, many of us have had issues running ASDM on the management port. The browser does not load ASDM.
This seems to be caused by the pressense of the following config:
ssl encryption des-sha1
Most browsers will reject the SSL connection with that cipher choice.
First make sure that you have the correct license installed and then correct the config line:
no ssl encryption des-sha1 ssl encryption rc4-sha1 aes128-sha1 aes256-sha1 3des-sha1