https://devzone.nordicsemi.com/f/nordic-q-a/206/128-bit-uuid-sHi, Function call to &gt; err_code = ble_advdata_set(&amp;advdata, NULL); returns always err_code = 7 (NRF_ERROR_INVALID_PARAMETER) for a 128 bit UUID type (BLE_UUID_TYPE_VENDOR_BEGIN). For 16 bit UUID types it works fine. Here is the code: #defineen-USTelligent Community 13Thu, 28 May 2015 15:04:09 GMThttps://devzone.nordicsemi.com/thread/1152?ContentTypeID=1Thu, 28 May 2015 15:04:09 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a6092fb8-28ce-424f-9491-f63956b16c42Jim Credland<p>This is really badly documented. You could usefully move this post to the bit that says &#39;Detailed Description&#39; here: <a href="https://devzone.nordicsemi.com/documentation/nrf51/4.3.0/html/group___b_l_e___u_u_i_d___t_y_p_e_s.html">devzone.nordicsemi.com/.../group___b_l_e___u_u_i_d___t_y_p_e_s.html</a> (and in similar locations for other SDK versions!)</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/1151?ContentTypeID=1Thu, 01 Aug 2013 09:01:11 GMT137ad170-7792-4731-bb38-c0d22fbe4515:95355b75-3373-49ec-88f1-b22009f4ea57Ole Morten<p>It seems you haven&#39;t added your custom base correctly. I just posted <a href="https://devzone.nordicsemi.com/index.php/how-can-i-use-a-vendor-specific-uuid">this question and answer</a> to properly explain how to add a base. If you follow this scheme, you must pass the type sd_ble_uuid_vs_add() retured instead of BLE_UUID_TYPE_VENDOR_BEGIN. If not, the softdevice will not be able to find out which base UUID should be used, and hence return an error.</p> <p>Note that you must also make sure that sd_ble_uuid_vs_add() is called before you set up the advertisement package. This most likely means that you should have your services_init() before your advertising_init() in main().</p><div style="clear:both;"></div>