https://devzone.nordicsemi.com/f/nordic-q-a/17168/how-to-keep-segger-rtt-viewer-open-while-downloading-firmwareSegger RTT viewer is a great debugging tool. But every time when I download new firmware into my board I have to close the viewer and then open it after download is finished. Otherwise it will cause errors in the viewer and eventually hang up the vieweren-USTelligent Community 13Wed, 19 Oct 2016 14:27:29 GMThttps://devzone.nordicsemi.com/thread/65964?ContentTypeID=1Wed, 19 Oct 2016 14:27:29 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3f4d5026-1a14-41c3-8012-bab244e65710Sigurd<p>Try to download the newest version, v6.00f, and see if that solves the problem.</p><div style="clear:both;"></div>