While it was built to meet the needs of modern ASA versions, it is backwards compatible with older ASA versions that do not yet enforce image signing. Why This Version Matters
There are reports of "Unable to validate the certificate of pdm.sgz file" during launch. Users have found workarounds by manually editing the run.bat file to point specifically to their installed Java directory rather than the built-in JRE. asdm-7181-152.bin