To draw the progress bar, XPGlobesOverlay.drawTooltipIfMouseover() uses Experience.getXPForLevel(), which threw an IllegalArgumentException when asked about level 1. This change shifts the XP_FOR_LEVEL array over by one, so that XP_FOR_LEVEL[0] is the XP required to reach level 1 (i.e. 0), rather than the XP required for level 2.