I have had a problem for years where my iMessage app will show a black screen whenever I try to access it. It renders me unable to view any messages whatsoever.
I have an iPhone 15 and I just updated to 26.3.1 (a) to see if it would fix it; it did not.
Did you also try to reset the iPhone to factory settings, to rule out, that the iOS software caused the issue?
To rule out defective data from the backup, set it up as a new device and set up and test the iMessage app again.
Restore your iPhone, iPad, or iPod to factory settings using a computer - Apple Support
Did you also try to reset the iPhone to factory settings, to rule out, that the iOS software caused the issue?
To rule out defective data from the backup, set it up as a new device and set up and test the iMessage app again.
Restore your iPhone, iPad, or iPod to factory settings using a computer - Apple Support
iMessage app shows black screen on iPhone 15
