https://devzone.nordicsemi.com/f/nordic-q-a/74885/crash-in-sdk15-2-that-was-not-in-sdk14-2-s132-segger-embeddedI am moving my project up to SDK15.2 from SDK14.2 and all is good except when I try to connect a ESP32 device. When connecting to the 14.2 code, I get this in the debug console: When connecting to the 15.2 code, I get this in the debug window: en-USTelligent Community 13Fri, 07 May 2021 20:49:02 GMThttps://devzone.nordicsemi.com/thread/308812?ContentTypeID=1Fri, 07 May 2021 20:49:02 GMT137ad170-7792-4731-bb38-c0d22fbe4515:7b48f338-f9ba-49da-84aa-74aad693b8eeBryan H<p>Fixed by removing the APP_ERROR_CHECK in the&nbsp;case BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST:</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/308802?ContentTypeID=1Fri, 07 May 2021 18:19:51 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8224f6e0-81b3-4cd6-8507-503aa28b7dc9Bryan H<p>Also, Line 1932 of main.c is APP_ERROR_CHECK(err_code); in the code below:</p> <p><pre class="ui-code" data-mode="text"> case BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST: err_code=sd_ble_gatts_exchange_mtu_reply(p_ble_evt-&gt;evt.gatts_evt.conn_handle, NRF_SDH_BLE_GATT_MAX_MTU_SIZE); APP_ERROR_CHECK(err_code); break;</pre></p><div style="clear:both;"></div>