pages

Apple pages (ver 11.2) closes automatically(return to home screen) every time i type on the paper, starting this morning. It doesn’t randomly close, only when i try to type something. i can still create new blank papers, erase what i’ve written the last days, or use other functions such as uploading, printing etc. Only when i open keyboard and try typing a letter, it closes.

My ipad version is 15.2.1 , I upgraded it to the latest version last night right before i sleep and when i wake up, boom, my pages app turns like that.

Is it something i should fix by myself or is it supposed to be fixed by developer?

If i am to fix it by myself, what should i do? Can someone help me??