4 Year Old Plugin Ninja Addon Manager No Longer Works in PHP 8.1+

Thanks for your comments. I was adding a new sticky post to the top of the support threads explaining this and when I finished it, I saw your post.

The add-on manager plugin is no longer supported. At some point the idea behind it might be brought back, but the plugin would need to be rewritten to address changes in Ninja Forms and PHP.

<3 Mia