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 is seen on ASA 5500-X boxes that have a factory config.
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