World won't sync

Not happy world is many years old and played with my kids lots of great memories plz help

What exact message do you get?

Can't sync worlds cloud data with your device.please check your connection and try again.

Very weird as I played only a few hours before this message 😔

I have even tried to open in realms but no luck

This issue is being tracked at MCPE-197900. It should be fixed when 1.21.100 is fully released.