This question is an exact duplicate of:
I encountered this situation a few times before, but I didn't care much. This is a bit annoying for mobile users, me alike.
Yesterday I added a comment to this answer using the Stack Exchange iOS mobile app, which was for my own question. After that, I was greeted with a blank page, which you can see below. Commenting was successful, and it's there. Why is this happening?
EDIT: I was made aware that this question already has an answer here, but it doesn't. The OP probably put their comment as an answer.
I am running version 220.127.116.11 of the app.