After the new Update of Minecraft PE the old Worlds I have do not work anymore I spend a lot of time on them and would like to still be able to play them can you see if you can fix this bug? It‘s also with my Friends Minecraft.

So i opened my Minecraft today and wanted to play Minecraft since the new Update is also available for the MCPE version.I wanted to open my World and it just loaded like about 5 Minutes or more. Plus I always have to go on a Server first before i can go on my World because 1. It first Crashes 2. I have ro go on a Server after and 3. It would only load after I was on the Server.