“This app contains an app extension with an illegal bundle identifier” issue

Question

I\'m a bit mixed up, since I changed the app name, Bundle Display name, and Bundle identifier name...and now my app works properly, but my today widget won\'t.

Whene

Answer 1

For me this due to the misnamed bundle identifier for my app extension. Similar to @dougbeal's answer, but slightly different formatting that worked for me:

com.company.AppName
com.company.AppName.Extension

I was missing the "." before Extension

This also addressed a related to issue