The Network creation panel is not for WordPress MU networks.

This problem has inexplicably resolved:

I clicking the nag warning, “Thank you for Updating! Please visit the Update Network page to update all your sites.” In the past, when I click on Update Network link, I got this error:
The Network creation panel is not for WordPress MU networks.

I also got the same error if I click on Network Admin from the upper right corner of the dashboard.

But things have changed. The link now goes to:

Warning! WordPress encrypts users cookies, but you must add the following line of code to wp-config.php for it to be more secure. Before the line /*That’s all, stop blogging! */ please add this code:
define( 'NONCE_KEY', 'REDACTEDFFS!' );

Once I followed those instructions, the nag went away and it gave me the option to update the network. I did so and all has been functioning well since. I don’t know why anything changed, but am happy it did.

I followed the directions to add the line of code to wp-config.php file. the refreshed the WP-admin page and the message about encrypting user cookies went away I tried the Update Network and it worked!

And now the link in the upper right to Network Admin works. 🙂

And after doing all noted above, I looked at the plugins and most of them looked like they needed to be Network Activated, so I did so with the plugins I knew we were using.

I think it all is functioning well now. This is a very welcome surprise!

Ipsenu, you did warn me but I didn’t realize that all keys were to be kept private. Ack! I was just trying to be responsible and report on how the problem was resolved. And now the forum will no longer let me edit or remove the post. I’m glad you say I am probably ok, but I will heed your warning and hide all my keys in the future. Thank you.

Thank you!! I’ll know better in the future.