Are you using Active Directory? This should have been recently addressed in Casper 8.5 but after looking through the release notes I don't see it mentioned.
Casper uses dscl to gather account names and will miss directory accounts because they are not stored locally. FUT should work. FEU, however, will only populate the currently logged-in user and the Casper admin account.
Casper 8.5 included a new setting that you can apply using Managed Preferences or the defaults command. Add this to Managed Preferences in the JSS and apply it to all your machines where you need FEU to work:
Domain: com.jamfsoftware.jamf
Apply Setting To: System Level Enforced
Key: append_users_not_in_dcsl
Value: true (boolean)
Alternately, you can run this command on each machine:
/usr/bin/defaults write /Library/Preferences/com.jamfsoftware.jamf append_users_not_in_dcsl -bool true
Note: The beta and release of 8.5 used "dcsl" instead of "dscl" in the key name above. This was bugged and I believe has been corrected as of version 8.52.
With this preference applied to a machine any .dmg packages you push that contain a /Users folder and where you have FEU set should install correctly for all user folders.
