I wanted to delete my testing Azure B2C directory, and followed steps to remove it at here and here. However, attempting to delete the directory, indicated that there was some app registrations preventing the deletion.
Clicking on the Required Action, I could see the Native ProxyIdentityExperienceFramework still existed. WHen I went ahead to delete it, I found out that the Delete button was disabled.
This app was created as part of configuring Azure B2C to use custom policies, as described here. App wasn’t a “converged app”, so it wasn’t visible in the Microsoft Application Console in order to delete it, as some suggested. I had also emptied the application of any Redirect URIs, Owners, Required permissions. Still the Delete button remained disabled.