Just thought to share some insights and tips on fixing this issue.
I had an old Macbook Air running High Sierra 10.13.6 that for some reason, stopped showing the installed printer icons in the Printer List when I tried to print something out but also not showing any printers at all in my network under the Add Printers section (Bonjour failed). So this is what I did.
1) Repaired drive permissions using Disk Utility
2) Rebuilt the Launch Services Database using this guide
3) Enabled CUPS in Terminal with this command: cupsctl WebInterface=Yes
4) Using the system plists from another working High Sierra build, replaced the following files on the main Macintosh HD just by copying them over using a USB stick:
/Library/Preferences/com.apple.networkextension.cache.plist
/Library/Preferences/com.apple.networkextension.plist
/Library/Preferences/com.apple.networkextension.necp.plist
/Library/Printers/InstalledPrinters.plist
With this, I could re-add all of my printers and the Printer & Scanner interface would work once again.
I had an old Macbook Air running High Sierra 10.13.6 that for some reason, stopped showing the installed printer icons in the Printer List when I tried to print something out but also not showing any printers at all in my network under the Add Printers section (Bonjour failed). So this is what I did.
1) Repaired drive permissions using Disk Utility
2) Rebuilt the Launch Services Database using this guide
3) Enabled CUPS in Terminal with this command: cupsctl WebInterface=Yes
4) Using the system plists from another working High Sierra build, replaced the following files on the main Macintosh HD just by copying them over using a USB stick:
/Library/Preferences/com.apple.networkextension.cache.plist
/Library/Preferences/com.apple.networkextension.plist
/Library/Preferences/com.apple.networkextension.necp.plist
/Library/Printers/InstalledPrinters.plist
With this, I could re-add all of my printers and the Printer & Scanner interface would work once again.
