The reported problem is a visual artefact (extra lines) generated by
ChainingIterators.pySketchyChainingIterator used for sketchy chaining with the Same Object
option disabled in the Parameter Editor mode. The issue is caused by an inconsistency in
the internal data structure (i.e., view map). For now this fatal error condition is addressed
to avoid visually incorrect results. Another fix will follow to address the cause of the
internal inconsistency.