Index: /issm/trunk/src/c/objects/Materials/Matice.cpp
===================================================================
--- /issm/trunk/src/c/objects/Materials/Matice.cpp	(revision 5883)
+++ /issm/trunk/src/c/objects/Materials/Matice.cpp	(revision 5884)
@@ -333,7 +333,7 @@
 
 	/*Checks in debugging mode*/
+	if(viscosity<=0) ISSMERROR("Negative viscosity");
 	ISSMASSERT(B>0);
 	ISSMASSERT(n>0);
-	ISSMASSERT(viscosity>0);
 
 	/*Return: */
@@ -404,7 +404,7 @@
 
 	/*Checks in debugging mode*/
+	if(viscosity3d<=0) ISSMERROR("Negative viscosity");
 	ISSMASSERT(B>0);
 	ISSMASSERT(n>0);
-	ISSMASSERT(viscosity3d>0);
 
 	/*Assign output pointers:*/
@@ -476,7 +476,7 @@
 
 	/*Checks in debugging mode*/
+	if(viscosity3d<=0) ISSMERROR("Negative viscosity");
 	ISSMASSERT(B>0);
 	ISSMASSERT(n>0);
-	ISSMASSERT(viscosity3d>0);
 
 	/*Assign output pointers:*/