Gon_Phishin Said:
"Thank You. I was going to rename the network, BUT I'll have to re-initialize every component in my Homekit. :-("
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You are welcome.
Thank you for the screenshot.
Troubleshooting "Common Network Name":
A. Ask the Manufacturer for Feedback:
Contact the Manufacturer of this device. You'll find their Contact Us info in the Home Page of their Web site. Rear back what they have to say on this. Usually, an email would do just fine.
B. Single-Out this User:
What happens when you create a new Administrator user? do you still get this error? If not, then it it like an issue with the configurations of the current user. If so, then it is an issue of the macOS, in which case, you'd need to reinstall it. Once done troubleshooting with it, you can simply just trash this user you've just created.
C. Single-Out this Mac:
What do other devices give you for this connection? If this Mac is only that is giving you this error, then it's an issue why your device --not the entire network.
D. Reinstall the macOS:
Go Here: How to reinstall macOS from macOS Recovery - Apple Support. Important: Be certain to create a backup of your Mac prior to all of this. That way, you can have something to restore from the Mac from, should anything go wrong with the reinstall. Once reinstalled, try this once more.
E. Restore from a Backup:
Any recent Backups?: If you backed up your Mac prior to updating it then, restore form it. Sometimes, an update can fail due to power issues, or losing connection to Apple's servers. So, know to always back up your Mac prior to making any major changes to it, successfully as au update. In doing so, you with have something to restore store your Mac from from, should anything go wrong with the upgrade.