UIApplication.sharedApplication not available
Problem solved. I've been to the Build Settings of my app again and stumbled over
Require Only AppExtension-Safe APIall set to YES. The default though is NO. When I set this to NO the error disappeared.
I sure don't remember ever touching or even knowing about this but luckily now it works.
I ran into the same error when I created and added a new target to my project (a Remote Service Notification target) and added the target definition incorrectly in my podfile.
I was following directions from a third party notification platform and they were unclear as to where to place the target definition. Initially, I added the target definition within my main target, much like the Tests target definition. This mistake led me to this error.
I ended up moving the remote service notification target definition outside of my main target to the bottom of my podfile and that resolved my problem.
In case anyone came through this error after 3 years from the question time.Make sure that the swift file target Membership doesn't include a Today Extension.