diff --git a/src/main/java/de/tla2b/TLA2B.java b/src/main/java/de/tla2b/TLA2B.java
index cd5b12104c6af88063d453c8227901aaf442bf2e..f411cf0caafa3ffa6c5457f6a07d75c9e8635e29 100644
--- a/src/main/java/de/tla2b/TLA2B.java
+++ b/src/main/java/de/tla2b/TLA2B.java
@@ -62,7 +62,7 @@ public class TLA2B implements TranslationGlobals {
 			System.err.println(e.getMessage());
 			System.exit(-1);
 		}
-		//translator.createMachineFile();
+		translator.createMachineFile();
 		translator.createProbFile();
 	}
 
diff --git a/src/main/java/de/tla2b/analysis/InstanceTransformation.java b/src/main/java/de/tla2b/analysis/InstanceTransformation.java
index 9fe8a1bf2aebc321d5ad7867711ffea54391bb76..a3848880a94c8c07602f146c7243f7a40d16953e 100644
--- a/src/main/java/de/tla2b/analysis/InstanceTransformation.java
+++ b/src/main/java/de/tla2b/analysis/InstanceTransformation.java
@@ -107,7 +107,7 @@ public class InstanceTransformation extends BuiltInOPs implements ASTConstants {
 
 		case StringKind: {
 			StringNode str = (StringNode) n;
-			return new StringNode(str.getTreeNode(), true);
+			return new StringNode(str.getTreeNode(), false);
 		}
 
 		case SubstInKind: {
diff --git a/src/main/java/de/tla2b/config/ModuleOverrider.java b/src/main/java/de/tla2b/config/ModuleOverrider.java
index b90e218bf0caaa96fe45925544d10243a7ad4c2f..d3a95f7d406af9c053f6ae8677fb008c8500f71f 100644
--- a/src/main/java/de/tla2b/config/ModuleOverrider.java
+++ b/src/main/java/de/tla2b/config/ModuleOverrider.java
@@ -177,13 +177,16 @@ public class ModuleOverrider extends BuiltInOPs implements ASTConstants {
 		case BuiltInKind:// Buildin operator can not be overridden by in the
 							// configuration file
 			ExprNode[] ins = n.getBdedQuantBounds();
-			for (int i = 0; i < ins.length; i++) {
+			if(ins != null){
+				for (int i = 0; i < ins.length; i++) {
 
-				OpApplNode res = visitExprOrOpArgNode(ins[i]);
-				if (res != null) {
-					ins[i] = res;
+					OpApplNode res = visitExprOrOpArgNode(ins[i]);
+					if (res != null) {
+						ins[i] = res;
+					}
 				}
 			}
+
 			break;
 
 		case UserDefinedOpKind: {