Minecraft PE WORLD crashes after adding texture pack City to the world.

• without, everything ist fine (launcher asks anyway for download city texture pack)
• with texture pack city everytime I start the game, the launcher wants to download the ressources (everytime, it seems to be lost between two sessions), downloads and installs it and starts the game an crashes suddenly when the world would be open.

This happens always but only in one specific world... and it first happened after the update of PE probably last thursday

I've already tried to uninstall and reinstall whole minecraft PE, I've tried also on a second device (same results).