https://devzone.nordicsemi.com/f/nordic-q-a/2712/dfu-over-air-failingHello, We are trying to implement a DFU with S110 V6 and SDK V5.2.0.39364. After starting the transfer procedure the nRF 51822 SoC restarts and disconnects. I tried out with both the MCP and the Toolbox 1.7 and 1.8 - results were the same. My phoneen-USTelligent Community 13Mon, 09 Jun 2014 19:28:53 GMThttps://devzone.nordicsemi.com/thread/10575?ContentTypeID=1Mon, 09 Jun 2014 19:28:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8ec482cd-5a57-4fc4-8004-afaff0cf5bf4Milko<p>Thanks John, But I think the problem is in Android 4.4, because I tryed same firmware with another smartphone with Android 4.3 and the DFU works with my device.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/10574?ContentTypeID=1Mon, 09 Jun 2014 19:23:28 GMT137ad170-7792-4731-bb38-c0d22fbe4515:987f3e10-9ca0-450c-8a7c-f0ac92ad6708John<p>Sounds like you are tripping over an ASSERT of some sort in the nRF51822. You can use the debugger to catch the call to the assert handler and see which file, line number and error code you are getting. I went as far as adding the ble_debug_assert_handler to my ASSERT handler and setting a breakpoint in the assert handler function. You would want to disable the debug assert handler before shipping product.</p><div style="clear:both;"></div>