Can't delete never used directories

I am trying to clean up our Azure subscription in preparation for a new project. I am the global administrator for the subscription.

In the past a couple of directories were created and never used. I have tried to delete them and and be unable to do so. In both cases. I get a message that I should Delete  all App registrations, even though there are no app registrations associated with either directory:

Does anyone know what is I am doing wrong?

Thanks in advance,

Rob