Index: /issm/trunk/src/c/parallel/convergence.cpp
===================================================================
--- /issm/trunk/src/c/parallel/convergence.cpp	(revision 3819)
+++ /issm/trunk/src/c/parallel/convergence.cpp	(revision 3820)
@@ -30,4 +30,7 @@
 	int    verbose;
 	double yts;
+
+	/*Check arguments*/
+	ISSMASSERT(Kff && pf && uf && old_uf);
 
 	/*get convergence options*/
@@ -65,9 +68,5 @@
 	res=nKUoldF/nF;
 	if (isnan(res)){
-		PetscSynchronizedPrintf(MPI_COMM_WORLD,"norm nf %lf \n",nF);
-		PetscSynchronizedFlush(MPI_COMM_WORLD);
-
-		PetscSynchronizedPrintf(MPI_COMM_WORLD,"norm kuold %lf \n",nKUoldF);
-		PetscSynchronizedFlush(MPI_COMM_WORLD);
+		_printf_("norm nf = %lf and norm kuold = %lf\n",nF,nKUoldF);
 		ISSMERROR("mechanical equilibrium convergence criterion is NaN!");
 	}
Index: /issm/trunk/src/c/parallel/diagnostic_core_nonlinear.cpp
===================================================================
--- /issm/trunk/src/c/parallel/diagnostic_core_nonlinear.cpp	(revision 3819)
+++ /issm/trunk/src/c/parallel/diagnostic_core_nonlinear.cpp	(revision 3820)
@@ -102,6 +102,5 @@
 		PenaltyConstraintsx(&constraints_converged, &num_unstable_constraints, fem->elements,fem->nodes,fem->vertices,loads,fem->materials,fem->parameters,analysis_type,sub_analysis_type); 
 
-		//if(verbose)_printf_("   number of unstable constraints: %i\n",num_unstable_constraints);
-		_printf_("   number of unstable constraints: %i\n",num_unstable_constraints);
+		if(verbose)_printf_("   number of unstable constraints: %i\n",num_unstable_constraints);
 
 		/*Figure out if convergence is reached.*/
@@ -127,8 +126,7 @@
 			break;
 		}
-
 	}
 
-	//more output might be needed, when running in control.c
+	//more output might be needed, when running in control
 	if(pKff0){