diff --git a/pact/pact-clients/resources/web-docs/launch.html b/pact/pact-clients/resources/web-docs/launch.html
index 3b8e86dddb511f34a2567476865d9654bb400ab1..e91de11495baea5721029271ff2246ea36791996 100755
--- a/pact/pact-clients/resources/web-docs/launch.html
+++ b/pact/pact-clients/resources/web-docs/launch.html
@@ -85,8 +85,7 @@
               type: "GET",
               url: "pactPlan",
               data: { job: id },
-              success: function(response) { showPreviewPlan(response); },
-              error:function (xhr, ajaxOptions, thrownError) { alert(xhr.responseText); pactPlanRequested = 0; }    
+              success: function(response) { showPreviewPlan(response); }
           });
         }
         else {
diff --git a/pact/pact-clients/src/main/java/eu/stratosphere/pact/client/nephele/api/PactProgram.java b/pact/pact-clients/src/main/java/eu/stratosphere/pact/client/nephele/api/PactProgram.java
index 6bf47225fe9c5c969413f60b7ebb96cb92d2a462..6507adcaf12b9105ad2a7472bb248c2d85e78c7a 100644
--- a/pact/pact-clients/src/main/java/eu/stratosphere/pact/client/nephele/api/PactProgram.java
+++ b/pact/pact-clients/src/main/java/eu/stratosphere/pact/client/nephele/api/PactProgram.java
@@ -121,7 +121,12 @@ public class PactProgram {
 	 * @throws ErrorInPlanAssemblerException
 	 */
 	public OptimizedPlan getPreOptimizedPlan() throws ProgramInvocationException, ErrorInPlanAssemblerException {
-		return getPreOptimizedPlan(getPlan());
+		Plan plan = getPlan();
+		if(plan != null) {
+			return getPreOptimizedPlan(plan);
+		} else {
+			return null;
+		}
 	}
 
 	/**
diff --git a/pact/pact-clients/src/main/java/eu/stratosphere/pact/client/web/PactJobJSONServlet.java b/pact/pact-clients/src/main/java/eu/stratosphere/pact/client/web/PactJobJSONServlet.java
index c50075e2e9634b1fbaf419d4169fbb2fe2635073..71bc43e7846b9ab1cc87408ba6c0aa3010c98c4c 100644
--- a/pact/pact-clients/src/main/java/eu/stratosphere/pact/client/web/PactJobJSONServlet.java
+++ b/pact/pact-clients/src/main/java/eu/stratosphere/pact/client/web/PactJobJSONServlet.java
@@ -73,17 +73,19 @@ public class PactJobJSONServlet extends HttpServlet {
 
 		// create the pact plan
 		try {
-			PactProgram pactProgram = new PactProgram(jarFile, (String[]) null);
+			PactProgram pactProgram = new PactProgram(jarFile, new String[0]);
 			OptimizedPlan optPlan = pactProgram.getPreOptimizedPlan();
-			String programDescription = pactProgram.getDescription();
-			String json = new JSONGenerator().compilePlanToJSON(optPlan);
-
+			String programDescription = pactProgram.getDescription();
+			
 			resp.setStatus(HttpServletResponse.SC_OK);
 			PrintWriter wrt = resp.getWriter();
 			wrt.print("{ \"jobname\": \"");
-			wrt.print(jobName);
-			wrt.print("\", \"plan\": ");
-			wrt.println(json);
+			wrt.print(jobName);
+			if(optPlan != null) {
+				wrt.print("\", \"plan\": ");
+				String json = new JSONGenerator().compilePlanToJSON(optPlan);
+				wrt.println(json);
+			}
 			if (programDescription != null) {
 				wrt.print(", \"description\": \"");
 				wrt.print(escapeString(programDescription));
diff --git a/pact/pact-examples/src/main/java/eu/stratosphere/pact/example/datamining/KMeansIteration.java b/pact/pact-examples/src/main/java/eu/stratosphere/pact/example/datamining/KMeansIteration.java
index 6bba10511f5ba390078e616e1275d03d56b0c741..9d738397ffdca0e47bb33c0dbd7024aa6263f0c7 100644
--- a/pact/pact-examples/src/main/java/eu/stratosphere/pact/example/datamining/KMeansIteration.java
+++ b/pact/pact-examples/src/main/java/eu/stratosphere/pact/example/datamining/KMeansIteration.java
@@ -631,17 +631,20 @@ public class KMeansIteration implements PlanAssembler, PlanAssemblerDescription
 	@Override
 	public Plan getPlan(String... args) {
 
+		int noSubTasks = 1;
+		String dataPointInput = "";
+		String clusterInput = "";
+		String output = "";
+		
 		// check for the correct number of job parameters
-		if (args.length != 4) {
-			return null;
+		if (args.length == 4) {
+			// parse job parameters
+			noSubTasks = Integer.parseInt(args[0]);
+			dataPointInput = args[1];
+			clusterInput = args[2];
+			output = args[3];
 		}
-
-		// parse job parameters
-		int noSubTasks = Integer.parseInt(args[0]);
-		String dataPointInput = args[1];
-		String clusterInput = args[2];
-		String output = args[3];
-
+		
 		// create DataSourceContract for data point input
 		DataSourceContract<PactInteger, CoordVector> dataPoints = new DataSourceContract<PactInteger, CoordVector>(
 			PointInFormat.class, dataPointInput, "Read Data Points");