Puybaret, thank you for looking into this.

Here is the error I get in the console. Again the same jar works fine with the stand alone.

Exception in thread "AWT-EventQueue-2" java.lang.LinkageError: loader constraint violation: loader (instance of com/eteks/sweethome3d/tools/ExtensionsClassLoader) previously initiated loading for a different type with name "com/eteks/sweethome3d/plugin/PluginAction"
at java.lang.ClassLoader.defineClass1(Native Method)
......