diff --git a/Common/processing.cpp b/Common/processing.cpp
index f7f9772..3a40b34 100644
--- a/Common/processing.cpp
+++ b/Common/processing.cpp
@@ -156,6 +156,18 @@ void Processing::AddFrequency(vector<double> *freqs)
 
 void Processing::DefineStartStopCoord(double* dstart, double* dstop)
 {
+	for (int n=0;n<3;++n)
+	{
+		double min = Op->GetDiscLine(n,0);
+		double max = Op->GetDiscLine(n,Op->GetNumberOfLines(n)-1);
+		if ( ((dstart[n]<min) && (dstop[n]<min)) || ((dstart[n]>max) && (dstop[n]>max)) )
+		{
+			cerr << "Processing::DefineStartStopCoord: Warning in " << m_Name << " (" << GetProcessingName() << ") : Box is outside the field domain!! Disabling" << endl;
+			Enabled = false;
+			return;
+		}
+	}
+
 	if (Op->SnapToMesh(dstart,start,m_dualMesh,m_start_inside)==false)
 		cerr << "Processing::DefineStartStopCoord: Warning in " << m_Name << " (" << GetProcessingName() << ") : Snapped start line outside field domain!!" << endl;
 	if (Op->SnapToMesh(dstop,stop,m_dualMesh,m_stop_inside)==false)
diff --git a/Common/processmodematch.cpp b/Common/processmodematch.cpp
index 30af21a..bce1435 100644
--- a/Common/processmodematch.cpp
+++ b/Common/processmodematch.cpp
@@ -79,6 +79,7 @@ void ProcessModeMatch::InitProcess()
 	m_Eng_Interface->SetInterpolationType(Engine_Interface_Base::NODE_INTERPOLATE);
 
 	int Dump_Dim=0;
+	m_ny = -1;
 	for (int n=0; n<3; ++n)
 	{
 		if (start[n]>stop[n])
@@ -94,19 +95,14 @@ void ProcessModeMatch::InitProcess()
 		if (stop[n]==Op->GetNumberOfLines(n)-1)
 			--stop[n];
 
-		if (stop[n]>start[n])
+		if (stop[n]!=start[n])
 			++Dump_Dim;
 
 		if (stop[n] == start[n])
 			m_ny = n;
 	}
 
-	int nP = (m_ny+1)%3;
-	int nPP = (m_ny+2)%3;
-	m_numLines[0] = stop[nP] - start[nP] + 1;
-	m_numLines[1] = stop[nPP] - start[nPP] + 1;
-
-	if (Dump_Dim!=2)
+	if ((Dump_Dim!=2) || (m_ny<0))
 	{
 		cerr << "ProcessModeMatch::InitProcess(): Warning Mode Matching Integration Box \"" << m_filename << "\" is not a surface (found dimension: " << Dump_Dim << ")" << endl;
 		SetEnable(false);
@@ -114,6 +110,11 @@ void ProcessModeMatch::InitProcess()
 		return;
 	}
 
+	int nP = (m_ny+1)%3;
+	int nPP = (m_ny+2)%3;
+	m_numLines[0] = stop[nP] - start[nP] + 1;
+	m_numLines[1] = stop[nPP] - start[nPP] + 1;
+
 	for (int n=0; n<2; ++n)
 	{
 		int ny = (m_ny+n+1)%3;