World Deleted On Its Own.

Every since the new aquatic update came out for minecraft my worlds have been deleted by themselves. In the past month 2 worlds have been deleted by themselves.

Both of the worlds worked fine and had no problems but for some reason when I launched my minecraft to play both of them were gone. I tried to sync old worlds but they still didn't appear.

The previous version worlds still remain but the new ones have gotten deleted.

Please can this get fixed because I had made a lot of progress on both worlds and they just deleted on their own.

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Version I was using when this took place was - 1.5.1 / 1.5.2