Sometimes after certain firmware upgrade or tweaking module settings, on Java modules like EHSx, people encountered error like this:

AT^SJMSEC?
+CME ERROR: Unknown 

Usually this is because the ^SCFG: "Userware/Autostart" has been turned-off.

To find out, one can check the output of AT^SCFG? and AT^SJAM=5, if both

• AT^SJAM=5 shows nothing is running and
• The output of AT^SCFG? is ^SCFG: "Userware/Autostart","0"

You can fix the issue with

 AT^SCFG="Userware/Autostart","","1" 

command.