I found the plugin with the problem. It was MailPoet Newsletters Thankyou very much for your help!

Hello! Thankyou for your response. It’s not a multisite, let me try the debug.log 🙂

The is no “Anspress registration of users”. Registration is handled by WordPress, so your error doesn’t come from Anspress. Maybe some conflict between plugins ? Enable WP debug.log mode and check for errors. (is that a multisite ?)

Hello, Yes, you are right. We don’t have users page in 4.x. As most of people are complaining about it. But it will be very easy to add it. Most of codes you can copy from top users widget.

Frank, that’s the exact issue I’m having as well.  So you’re not alone on this problem, and none of the beta versions seem to fix this either.   I’m very close to giving up on Anspress 4 and going back to the older version.

Hello Cagliostro, Thanks for reporting the issue. I fixed it. Cheers.