user unable to connect wireless network with errors APF-1-USER_ADD_FAILED

[Foo Chuan Soon]

there are many events logs related to user add failed today, can anyone please help to explain what is this error message about?
 Thanks. 
 
 

Sep 29 10:02:28.091 apf_ms.c:4776 APF-1-USER_ADD_FAILED: Unable to create username ASIA-PACIFIC\Surya_Dharamdass for mobile00:24:2b:a0:e2:49

Sep 29 10:02:28.083 apf_ms.c:4776 APF-1-USER_ADD_FAILED: Unable to create username ASIA-PACIFIC\Hour_Sou_Cheng for mobile18:3d:a2:3b:6e:8c

Sep 29 10:02:27.970 apf_ms.c:4776 APF-1-USER_ADD_FAILED: Unable to create username ASIA-PACIFIC\Sherene_Chan for mobile00:23:4d:1a:56:ac

Sep 29 10:02:27.895 apf_ms.c:4776 APF-1-USER_ADD_FAILED: Unable to create username ASIA-PACIFIC\Kai_Choo_Wong for mobile18:3d:a2:25:e5:2c

Sep 29 10:02:27.786 apf_ms.c:4776 APF-1-USER_ADD_FAILED: Unable to create username ASIA-PACIFIC\Madhura_Marippan for mobilef0:7b:cb:73:3d:4d

[Kayle Miller]

This error indicates that the controller was unable to create a username entry internally for this mobile device, it could be a number of things that are causing this. \

• Is this a new issue or has this been happening for sometime?
  
• Is this a new network or has it been in production for some time?
  
• Is this happening to every client?
  
• What type of security on the SSID in question?