When upgrading the LDMS core to 9.6 the prerequisite check fails if there is a full agent installed.
Run uninstallwinclient.exe from c:\program files (x86)\landesk\management suite\ldmain\
*DO NOT RUN UNINSTALLWINCLIENT.EXE WITH ANY SWITCHES*
The /forceclean switch will delete all the core certificates and are not recoverable unless there is a backup saved elsewhere.
If the keys folder is missing (c:\program files (x86)\landesk\shared files\keys\) the core upgrade will fail.