My Minecraft worlds never synchronize, when reaching 77% synchronization it shows an error. And the truth is that I only care about one of those worlds since it is my main survival world, the worst of all is that this particular world is synchronized without problems by the Minecraft preview, that is, how is it possible that the beta version loads it without problems and the normal version does not?.

I already uninstalled and reinstalled the game several times and nothing is solved.