If I attempt to remove the route point inside the stable slope selector, it is removed with no problem and the world can be saved/loaded successfully – so an example world where attempting to remove a route point causes problems would be highly useful.
I also could really use a more specific set of actions to take: For example, are you deleting the route points by right clicking on them and choosing “Remove Route Point”, or are you deleting the wire they exist on (and if the latter, is it being deleted by right clicking on the wire, disconnecting the port, or other…)