After saving and quitting from my world, it won't show up under my singplayer worlds anymore. This has happened twice and I've tried to recover both through %appdata%, but all it says is that there are "no previous versions available" of my world. How can I recover these worlds if this is not working?
There is a workaround on MC-193198 - if it constantly happens to you, please provide the console log from the exact moment a world has gone missing on the parent report.