Eclipse error 249 related to Quartus 11.1sp2

In Eclipse of Quartus 11.1sp2, when I execute the following commands from menu: RUN \ DEBUG(RUN) CONFIGURATIONS \ NIOSII HARDWARE

I get the following error message:

'An error occurred while automatically activating bundle com.altera.sbtgui.launch (249) '

Does anybody tell me something ?

thanks.

koletta