I found the fix to this issue on bug number MCPE-20077. I have listed it below. This fix worked for me.
Isioma Akaeze added a comment - 19/Feb/17 2:44 AM How to fix: Open Minecraft PE. Look around and press Store button. Swipe down to the bottom of the page and click Restore.(Make sure you're connected to the internet). If it asks you to sign in, sign in with your password for Itunes. If it says successful, go to settings and put texture pack on. If not, tell me what happened.
I bought the Fall-Out mash-up pack for my daughters iPad Air 2. She played it multiple times. She did not report that the app crashed. Today she brought her iPad to me and showed me that the mash-up is now locked.
I found the fix to this issue on bug number MCPE-20077. I have listed it below. This fix worked for me.
Isioma Akaeze added a comment - 19/Feb/17 2:44 AM
How to fix: Open Minecraft PE. Look around and press Store button. Swipe down to the bottom of the page and click Restore.(Make sure you're connected to the internet). If it asks you to sign in, sign in with your password for Itunes. If it says successful, go to settings and put texture pack on. If not, tell me what happened.