Reach Fix fixes a few bugs of Minecrafts entity hit detection. There are some situations where the player should be able to hit an entity but isn't able to. This fix is more noticeable against bigger entities. Also, entity bounding boxes are now interpolated to match the entity model.
Now the reach attribute is taken into consideration when targeting an entity instead of only when targeting a block.
This mod also adds a config option to allow you to change the base reach of players when in survival and creative mode.
Compatibility with Potion Core:
If you are using Potion Core then you have to go into the Potion Core config and disable "Fix Reach".