ltad

Thanks for the quick reply.

Just popping in to say I had this same issue. As long as the plugin isn’t active on the root site of the multisite network everything functions as expected. I was able to use the Multisite Plugin Manager to mass re-activate the plugin after network deactivating it and then only had to deactivate again at the root for anyone who uses this widely on a multisite network.

@walkingpaper — yes, I managed to solve this but haven’t had time to follow up.

On my multisite the plugin “The Event Calendar” was active on my root site as a site-level plugin. As soon as I disabled that plugin on that site everything was working. Until December this was a network enabled plugin with no issues, but something in the 6.4.3 of Core with that plugin on the root site was causing new sites not to create correctly. I have the plugin still installed and deployed to a couple hundred sites on my network but if it’s network enabled or is enabled on the root site of the multisite it breaks new site creation.

Hope that helps you. I ended up disabling all plugins that weren’t network enabled on my root site just to be safe but I could reliably reproduce the problem by enabling The Event Calendar on that site.