Index: /issm/trunk-jpl/src/m/classes/masstransport.py
===================================================================
--- /issm/trunk-jpl/src/m/classes/masstransport.py	(revision 24287)
+++ /issm/trunk-jpl/src/m/classes/masstransport.py	(revision 24288)
@@ -74,5 +74,6 @@
         md = checkfield(md, 'fieldname', 'masstransport.min_thickness', '>', 0)
         md = checkfield(md, 'fieldname', 'masstransport.requested_outputs', 'stringrow', 1)
-        md = checkfield(md, 'fieldname', 'masstransport.vertex_pairing', '>', 0)
+        if not np.any(np.isnan(self.vertex_pairing)):
+            md = checkfield(md, 'fieldname', 'masstransport.vertex_pairing', '>', 0)
 
         return md
Index: /issm/trunk-jpl/src/m/classes/stressbalance.py
===================================================================
--- /issm/trunk-jpl/src/m/classes/stressbalance.py	(revision 24287)
+++ /issm/trunk-jpl/src/m/classes/stressbalance.py	(revision 24288)
@@ -134,5 +134,6 @@
         md = checkfield(md, 'fieldname', 'stressbalance.loadingforce', 'size', [md.mesh.numberofvertices, 3])
         md = checkfield(md, 'fieldname', 'stressbalance.requested_outputs', 'stringrow', 1)
-        md = checkfield(md, 'fieldname', 'stressbalance.vertex_pairing', '>', 0)
+        if not np.any(np.isnan(self.vertex_pairing)):
+            md = checkfield(md, 'fieldname', 'stressbalance.vertex_pairing', '>', 0)
         #singular solution
         #        if ~any((~isnan(md.stressbalance.spcvx) + ~isnan(md.stressbalance.spcvy)) == 2),