@woodcutter It locks your view to the given values, basically it makes your mouse not do anything and only w a s d works and your view is locked to whatever it is set to, you can turn one of them on/off to only have one of the directions locked.
@binjamin6 Can you give more details on "wouldn't work"? like what exactly went wrong, also could you follow this video ^ and send your log link so we can see what's causing this problem