The file windowPositionAndSizeConfig.tag seems to corrupt sporadically, causing the game to completely fail to start, until the file is either erased or the default world's name is changed(the file seems to store the data on a per-world basis, so changing the world's name will either point to an uncorrupted section of the file, or cause a new section to be generated with default values).
What causes the file to be corrupted is unknown though, and feedback regarding that is appreciated.