My son's iPad won't launch Minecraft PE after the 7/21/18 update. No issues before the update.  He uses it daily and a lot. I see forum posts with similar issues. Searched and didn't see a JIRA ticket.

We see the Mojang logo, then the Minecraft logo before it crashes. No error messages. Has rebooted iPad several time, nothing else is running. iPad2, 16 GB, 3.7 GB free. iOS 9.3.5 (latest). Minecraft PE 1.5.1. (7/21/18). He has 1.1 GB Minecraft docs, >400 worlds.