SAP MII Applet error--java.lang.IndexOutOfBoundsException: Index: 0,Size: 0

Dear Experts,

I am facing java error while running an iCommand applet through irpt page in SAP MII 12.1

By forum ,  I came to know ,the error occurs because of using the method "document.AppletName.getRowCount()" before executeCommand().

if(document.AppletName.executeCommand()){

  rowCount = document.AppShopfloorCmd.getRowCount();

}

any idea on how to resolve the following error :

Message: java.lang.IndexOutOfBoundsException: Index: 0, Size: 0

Should I need to re-install the java ?

this error is machine or Application specific ?

Regards,

Eswar