when a hot runner is added from a another model, it might happen that
a) the old trigger nodes are in the new model,but are not connected and the valve gate is referring to the old nodes.
b) or the valve gate is referenced to the old node that doesnt exist in the new model
in case of a) the valve gate wont open
in case of b) the simulation will fail
either way this can be easily checked beforehand with a simple check tool or pointed out in the mesh statistics
