Admin menu capability does not exist and generates an error with Freesoul Deactivate plugin

As per this forum post: Admin menu capability
Customer states:

”At line 48 of the file classes/WpMatomo/Admin/Menu.php you define const CAP_NOT_EXISTS = ‘unknownfoobar’;
Please, check this file:
https://plugins.trac.wordpress.org/browser/matomo/tags/4.12.0/classes/WpMatomo/Admin/Menu.php#L48

Then at line 77 of the same file, you add an admin menu page using the capability “unknownfoobar”:
This is your code:

add_menu_page( 'Matomo Analytics', 'Matomo Analytics', self::CAP_NOT_EXISTS, 'matomo', null, 'dashicons-analytics' );

It looks like nowhere in your plugin you add the capability “unknownfoobar”. At least, I don’t see it anywhere.
Can I ask you why you are adding an admin menu item with a capability that doesn’t exist?

I opened this thread because your plugin generates a conflict with Freesoul Deactivate Plugins. With FDP you can selectively disable plugins, and it rebuilds the admin menu in the backend. But becausee the logged user hasn’t the capability “unknownfoobar”, the admin menu item added by your plugin is missing when FDP is active.”

Read classes/WpMatomo/Admin/Menu.php around lines 48 and 77, then review the linked forum report and the interaction with Freesoul Deactivate Plugins. Done means the Matomo admin menu behaves correctly when the plugin rebuilds the backend menu, while retaining the intended access restrictions.