Making changes in one model can result in other models being marked as changed even though they are unmodified by the user. In the reproduction steps, making a change to a transformation in one model results in changes to a related model that is unmodified by the user. When closing and discarding changes in the related model, additional changes (not initiated by the user) are made to the original model. These Eclipse-initiated changes seem to result in reference errors when building the model if they are saved.