https://devzone.nordicsemi.com/f/nordic-q-a/27079/hid-keyboard-exampleHi all. i am using hid device keyboard example for nrf5. But when I try to call sd_ble_gatts_hvx(p_hids-&gt;conn_handle, &amp;hvx_params), this function returns error code 0x00003401. This function is in ble_hids_inp_rep_send, which call when Button 0 presseden-USTelligent Community 13Sat, 08 Apr 2017 00:25:08 GMThttps://devzone.nordicsemi.com/thread/106454?ContentTypeID=1Sat, 08 Apr 2017 00:25:08 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8b36a64e-0106-4206-953a-e78b03f2d40eVadimSavchuk<p>Thank you. But I have another question.. After disconnect from chip I can not connect while I am not restart nrf51. In what may be problem?</p> <p>I have not many experience with bluetooth</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/106453?ContentTypeID=1Wed, 05 Apr 2017 09:17:28 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b76f364b-9b81-4eaa-8de0-1f46159d0ef4Sigurd<p>Hi,</p> <p>Error code <code>0x00003401</code> is <code>BLE_ERROR_GATTS_SYS_ATTR_MISSING</code>.</p> <p>See <a href="https://devzone.nordicsemi.com/question/102665/ble_error_gatts_sys_attr_missing-from-sd_ble_gatts_hvx/">this</a> answer and <a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v3.0.0/group___b_l_e___g_a_t_t_s___h_v_x___s_y_s___a_t_t_r_s___m_i_s_s_i_n_g___m_s_c.html?cp=2_3_0_1_1_2_4_3_4">this</a> MSC for how to handle it. And <a href="https://devzone.nordicsemi.com/question/6085/strange-error-code-13313-0x3401-returned-by-sd_ble_gatts_hvx/">this</a> and <a href="https://devzone.nordicsemi.com/question/120775/ble-app-blinky-ble_error_gatts_sys_attr_missing/?answer=121097#post-id-121097">this</a> for some more information.</p><div style="clear:both;"></div>