Index: /issm/trunk-jpl/src/m/classes/model.m
===================================================================
--- /issm/trunk-jpl/src/m/classes/model.m	(revision 19123)
+++ /issm/trunk-jpl/src/m/classes/model.m	(revision 19124)
@@ -1015,9 +1015,9 @@
 
 			%New fields
-			if ~isfield(structmd,'upperelements');
+			if ~isfield(structmd,'upperelements') & isa(md.mesh,'mesh3dprisms')
 				md.mesh.upperelements=transpose(1:md.mesh.numberofelements)+md.mesh.numberofelements2d;
 				md.mesh.upperelements(end-md.mesh.numberofelements2d+1:end)=NaN;
 			end
-			if ~isfield(structmd,'lowerelements');
+			if ~isfield(structmd,'lowerelements') & isa(md.mesh,'mesh3dprisms')
 				md.mesh.lowerelements=transpose(1:md.mesh.numberofelements)-md.mesh.numberofelements2d;
 				md.mesh.lowerelements(1:md.mesh.numberofelements2d)=NaN;