Impossible for us to know for sure without being able to try with your specific install. I have to assume you’re trying to register the post type, and not create a new post in the post type.
The “I’m trying to migrate” option is for if you have the post type also registered via other means, like with a different plugin or via register_post_type() and is meant to override the built prevention due to the post type already being registered elsewhere.
Is that the case for your situation? You have “testimonials” registered elsewhere and you want to move the registration into CPTUI?
Beyond that, not sure what would be going on at the moment, as “testimonials” isn’t a disallowed slug.
Thanks for your response. I ended up getting a list of all my registered post types and then completely removed “testimonials”. I also did a fresh install of CPT UI, and now everything is working as expected.
My guess is that I somehow already had “testimonials” registered, so when I went to register it again through your plugin, it was getting stuck.
I appreciate the quick response, and keep up the great work with the plugin. I use it frequently and have never had any issues, other than this one which was most likely of my own doing.
Thanks, Michael!