diff --git a/converter-CellDesigner/src/main/java/lcsb/mapviewer/converter/model/celldesigner/CellDesignerParserException.java b/converter-CellDesigner/src/main/java/lcsb/mapviewer/converter/model/celldesigner/CellDesignerParserException.java
index 9687b0fdf87b096646f303aaaf3989a8fdeea994..fa08dbc952962ac9215b98fb2ba3491aebcd91e8 100644
--- a/converter-CellDesigner/src/main/java/lcsb/mapviewer/converter/model/celldesigner/CellDesignerParserException.java
+++ b/converter-CellDesigner/src/main/java/lcsb/mapviewer/converter/model/celldesigner/CellDesignerParserException.java
@@ -56,7 +56,13 @@ public abstract class CellDesignerParserException extends Exception {
   }
 
   public String getMessageWithContext() {
-    return getMessageContext() + " " + this.getCause().getMessage();
+    String message;
+    if (this.getCause() != null) {
+      message = this.getCause().getMessage();
+    } else {
+      message = this.getMessage();
+    }
+    return getMessageContext() + " " + message;
   }
 
   public abstract String getMessageContext();