From: https://support.addigy.com/hc/en-us/articles/8348546682899-System-Update-s-Not-Working
Running Updates on Macbooks will result with no updates available as shown below.
 
 
Via liveterminal ran:
Sudo /bin/launchctl kickstart -k system/com.apple.softwareupdated
And
 
Sudo mv /Library/Receipts/InstallHistory.plist /Library/Receipts/InstallHistory.plist.old
This fixed the issue to Edwardo’s Macbook. Make sure you refresh the Addigy webpage before checking for updates again.


Thanks,

Audel