Using ASDM, we see the message ‘Unable to launch device manager from x.x.x.x’
At the time of writing this has been tracked back to an update in Java. Recent versions have disabled TLS 1.0 and TLS 1.1
Apparently later versions of ASDM do not have this problem, but of course you need initial access in order to do an upgrade.
If you turn on the Java console, you should be able to see the error refering to being unable to negotiate tls10.
In order to regain access;
edit the file java.security which is located in jre/lib/security or /conf/security
Search for the key jdk.tls.disabledAlgorithms
Remove the entries for TLSv1 and TLSv1.1
Once upgraded, remember to turn back on the above disabled algorithms.