https://devzone.nordicsemi.com/f/nordic-q-a/125657/upgrading-sdk-2-6-1-to-3-1-1-broke-mcumgrI upgraded my sdk from 2.6.1 to 3.1.1 and after resolving a few issues everything was working just as it was before the upgrade except for MCUmgr. When I run the MCUmgr client on my PC after the upgrade, the server on the nRF52850 does not reply to anyen-USTelligent Community 13Tue, 18 Nov 2025 19:37:04 GMThttps://devzone.nordicsemi.com/thread/554713?ContentTypeID=1Tue, 18 Nov 2025 19:37:04 GMT137ad170-7792-4731-bb38-c0d22fbe4515:fec54da0-8d1a-453c-bd75-982301225f43robert.grady<p>I dug around for a while and found some new Kconfigs that needed to be set.&nbsp;&nbsp;</p> <div> <div><span>CONFIG_MCUMGR_TRANSPORT_BT_PERM_RW</span><span>=y</span></div> <div> <div> <div><span>CONFIG_BT_SMP_SC_PAIR_ONLY</span><span>=n</span></div> <div></div> <div>Working fine now.</div> </div> </div> </div><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/554598?ContentTypeID=1Mon, 17 Nov 2025 19:51:03 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5b96779d-7c60-45ad-8186-54bc7e9247c9nordicator_prim3<p>I remember running into this as well when upgrading from 2.6.0 to 2.8.0. I had originally based my mcumgr functionality on the smp_svr example. After trying to upgrade I had to get the smp_svr sample from 2.8.0 which had some different Kconfigs and subtly different app structure. I would try looking at the sample app with the version you wanted to use.</p> <p>Any changes that happened between releases should be in the <a href="https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/releases_and_maturity.html">release notes and migration guides</a> if you haven&#39;t checked there yet. If they aren&#39;t there in the nordic docs you may have to check the release notes from the actual zephyr repo as well. That&#39;s a pain sometimes, so I&#39;d recommend looking at the smp_svr example first.</p> <p>Hope this helps.</p><div style="clear:both;"></div>