I have been using Dropbox and Boxifier for PC along with Dropsync for Android to keep my worlds in sync between my Galaxy S4 with 0.14.0 Beta 6 and my Windows 10 laptop with v0.13.1.
Before joining the beta, I turned off the sync so that I could work with worlds on my phone in the beta without making them unplayable on my laptop. Later, I chose to "restore" all of the worlds on my phone by just copying the older versions of them on my laptop. I made sure to completely get rid of the world files from my phone and then copy the world files from my laptop. I figured that this should have worked fine because the worlds that were coming from my laptop were technically just versions of the worlds my phone had before I joined the beta (my phone had v0.13.1 if I'm right, as well as my laptop).
The problem is that now on my phone, with random worlds that I restored, I get an error that says "[World name] can't be opened." The affected worlds will still open perfectly fine on Windows 10 though.
Comments 2
Copying over the world files is not sufficient for restoring an old backup of a world. To properly restore a backup of a world, you must first delete the world in the list of worlds in the game, quit the game, restore the backup files and then restart the game. Strange things happen when you simply replace the files without first deleting the world from the world list. Stranger things happen if you do that while MCPE is open!
To fix, delete one of the "can't be opened" worlds from the worlds list, quit MCPE, then restore the backup files for that world and try again. If you still have issues, comment back here again.
Copying over the world files is not sufficient for restoring an old backup of a world. To properly restore a backup of a world, you must first delete the world in the list of worlds in the game, quit the game, restore the backup files and then restart the game. Strange things happen when you simply replace the files without first deleting the world from the world list. Stranger things happen if you do that while MCPE is open!
To fix, delete one of the "can't be opened" worlds from the worlds list, quit MCPE, then restore the backup files for that world and try again. If you still have issues, comment back here again.