: Be aware that "1.11.2" Eaglercraft often still identifies as 1.8.8 in the debug menu ( ) because it is a modded version of the older client.
A: Eaglercraft saved data to the browser's local storage (IndexedDB). If you cleared your browser cache or history, your singleplayer world was deleted. Unlike the official game, there was no cloud backup unless you manually downloaded the world file.