Minecraft no longer starts on ipad 3 after update

not sure which minecraft I needed to pick for the ios version, but since the 29-10-2019 update it won't start on my ipad 3 with iOS 9.3.5. My son is in tears because his hard work appears to be gone. I expected that I could access the realms through the account on a newer iPad, but this is apparently not the case.

1. Please fix this new bug, so Minecraft starts on ipad 3 with iOS 9.3.5
2. how can I make the realms accessible through the account?