Pathways include gpml objects in the node table that are not real nodes, and therefor don't have a name. This breaks the SIF export. The export should work, at least for pathways imported as networks. Even these networks include anchor nodes with no name. A simple fix could be to add a name to all nodes to make the SIF export work.
See https://github.com/cytoscape/cytoscape-manual/issues/51
Pathways include gpml objects in the node table that are not real nodes, and therefor don't have a name. This breaks the SIF export. The export should work, at least for pathways imported as networks. Even these networks include anchor nodes with no name. A simple fix could be to add a name to all nodes to make the SIF export work.