https://devzone.nordicsemi.com/f/nordic-q-a/84731/code-crashed-inside-otmessageread-in-otcoapsendrequest-s-callback-functionHi, I am using &quot;otCoapSendRequest&quot; to send data to my coap server. Inside the callback, I am using otMessageRead, to read the response. But my code crashed inside otMessageRead. If I comment this line then my code runs smoothly. Following is theen-USTelligent Community 13Mon, 14 Feb 2022 14:51:48 GMThttps://devzone.nordicsemi.com/thread/352936?ContentTypeID=1Mon, 14 Feb 2022 14:51:48 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5491abf5-6867-436d-821d-e58aaca74b98Edvin<p>Hello,</p> <p>Do you know exactly what function that you added that trigger this fatal error?</p> <p>If not, you can look into the tool addr2line from&nbsp;GNU Arm Embedded Toolchain (which you probably have installed, but may not be in your PATH.</p> <p>The addresses you want to check using this tool is the address from r15/pc (the actual address may change when you recompile, so check your latest log). In this case it was 0x00056520. To check it, use this in your command line:</p> <p><pre class="ui-code" data-mode="text">arm-none-eabi-addr2line -e zephyr\zephyr.elf 0x00056520</pre></p> <p>from inside your build folder.&nbsp;</p> <p>You can also check the address in r14/lr, which is the address of the function calling the function that triggered the error.&nbsp;</p> <p>What line/function is it pointing to?</p> <p>Best regards,</p> <p>Edvin</p><div style="clear:both;"></div>