Unclear message when URL for non-existing admin page is called

[tobifjellner]

If you try to visit the admin page of a plugin that is currently inactive, then currently (WordPress 6.2) the error message given is:

Sorry, you are not allowed to access this page.

Even though in this case there may not even be such a page defined.
I got this message when I followed a link to the settings page of a plugin that had automatically disabled itself.
A user misunderstood this message in ​https://wordpress.org/support/topic/after-plugin-disabled-sorry-you-are-not-allowed-to-access-this-page/
One may reach this message if following an outdated bookmark to a plugin's admin page.

If possible, this particular case "There is currently no such admin page defined in this system." would be a better, and more actionable message.

[costdev]

Hi @tobifjellner, thanks for opening this ticket.

Messaging was unified as part of #34521. Setting the Version property to 4.6.