Problem uploading to board

Hey guys. I'm new here. maybe you can help me. I've got an Arduino Due and if i want to upload my project (Dimmer), there is always the same problem:

avrdude: stk500_recv(): programmer is not responding
processing.app.debug.RunnerException: Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.
at processing.app.debug.BasicUploader.uploadUsingPreferences(BasicUploader.java:126)
at processing.app.Sketch.upload(Sketch.java:1649)
at processing.app.Sketch.exportApplet(Sketch.java:1608)
at processing.app.Sketch.exportApplet(Sketch.java:1580)
at processing.app.Editor$DefaultExportHandler.run(Editor.java:2408)
at java.lang.Thread.run(Thread.java:680)

What does it mean and how can i clear it?

thanks for your help

I'm having the exact same problem. Any help would be appreciated.

did you ever figure this one out? I'm having that problem now too.