Did this ever get resolved? I'm experiencing the same issue on an ASA that I used to be able to get to via ASDM. I've tried it from two different computers from two different subnets via ASDM launcher and HTTPS. Any help would be appreciated.
Well at the end I had to reload the ASA and then everything went back to normal, in fact I receive help from CISCO TAC and the told me that we need to install the lastest IOS version on the device because there was a bug on the version that we were using.