You must have used splitting of any entity. If not check this “Splitting an Entity”. Now say while doing this, you created an extra split which was not required and if you try to delete, it delete that portion of the entity. Here is quick trick to delete that extra/unwanted split point.
1. Select the split entity point you want to delete.
2. Hit Delete on the keyboard.
3. Great you have the entity got rid of that unwanted split point. If you want to remove multiple points, then Ctrl select them and hit Delete on the keyboard.