When attempting to open a world where the level.dat read operation fails, a toast will appear indicating that the world load has failed. However, the game remains on the 'Reading world data...' screen, and the player cannot perform any other actions, such as closing the world load screen. The only option remaining is for the player to relaunch the game entirely.

The expected behavior is for the game state to be recoverable; that is, another world can be attempted to be loaded after the load for the current world fails. I believe this is a valid bug as filesystem issues should be recoverable where possible, and the game should never softlock itself.