World not working even in B snapshot

There are screenshot in the attachment

I have a Youtube series on my channel, I don't load my world on 19a, but it says "you can open your world in 19b" on minecraft.net. DOESN'T WORKS! Even my pickaxe haven't got Silk Touch and Mending on it. And my inventory is... uh... As not mine. Is Minecraft backed my world from 1 month?