https://devzone.nordicsemi.com/f/nordic-q-a/29681/softdevice-nrf_fault_id_sd_assert-during-gdb-debug-sessionHi, I found my debug session keeps reset due to this error (code jump into app_error_fault_handler) when I stepped through my code. This happens at random places. I&#39;m not my code can cause this issue. What is this error? How can I fix or avoid it? en-USTelligent Community 13Tue, 23 Jan 2018 03:38:22 GMThttps://devzone.nordicsemi.com/thread/117808?ContentTypeID=1Tue, 23 Jan 2018 03:38:22 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e43354b1-a08d-4394-93d1-fdce8928974eRK<p>You can&#39;t debug with the softdevice running, at least not if it&#39;s actually doing anything like either advertising or in connection. It has very strict timing requirements and as soon as you halt it in the debugger it will fail internal checks when it gets going again.</p> <p>You need to debug either with RTT or just putting one breakpoint in and looking at the registers at that point only or , if you are on an nRF52 chip, look at the blog posts about Monitor Mode Debugging which will let you debug with the softdevice running.</p><div style="clear:both;"></div>