Troubleshooting Tip: Error 'ERR: NO MEM for USER_LOCAL_MSG' in wireless-controller debugs.

Execute the WTP debugs on the FortiGate to find at which point the FortiAP connection is failing, where x.x.x.x is the IP address of the FortiAP:

diagnose wireless-controller wlac wtp_filter <FAP_SerialNumber> 0-x.x.x.x:5246 2

diagnose debug application cw_acd 0x7ff

diagnose debug console timestamp en

diagnose debug enable

The following error message will be observed in the debugs:

2025-10-15 09:45:20 52409.715 266 --- ==========================cwAcProcInputLocalMsg 17 1=========================
2025-10-15 09:45:20 52409.715 266 ERR: NO MEM for USER_LOCAL_MSG
2025-10-15 09:45:20 52409.715 266 --- ERR: NO MEM for USER_CTLMSG_UDP_RECV

If this error appears in the debugs, execute the following command to check if the cw_acd process is consuming high memory:

FGT-A # diagnose sys top 2 5

Run Time: 0 days, 19 hours and 17 minutes
0U, 0N, 0S, 100I, 0WA, 0HI, 0SI, 0ST; 1917T, 655F
             cw_acd        192      S      2.4       81.7      3
              httpsd       958      R      0.4       1.3       3
              httpsd       964      S      0.4       1.0       3
          ipshelper        191      S <     0.0      2.6       7
                 wad       326      S      0.0       1.7       7

To recover the wireless-controller service:

Kill the above process using below methods:

• Killing all cw_acd processes using the following command:

fnsysctl killall cw_acd

• Restarting the process using the below command:

diagnose sys process pidof cw_acd   <----- To find the process-id.

diagnose sys kill 11 <p_id>             <----- p_id is output of above command

Related article:

Technical Tip: High memory due to the cw_acd process and potential causes