Failed to authenticate an Active Directory User

[TOURE Amidou Florian]

Hi all ,When trying to authenticate a user against Active Directory I got this errorMon Apr  4 10:37:21 2016 : Auth: Login incorrect: [Prof-PC\\Prof] (from client 192.168.1.5/255.255.255.0 port 50002 cli 00:40:d0:67:d0:b1)
Mon Apr  4 10:39:45 2016 : Auth: Login incorrect (mschap: External script says Logon failure (0xc000006d)): [Prof-PC\\Prof] (from client 192.168.1.5/255.255$
Mon Apr  4 10:39:45 2016 : Auth: Login incorrect: [Prof-PC\\Prof] (from client 192.168.1.5/255.255.255.0 port 50002 cli 00:40:d0:67:d0:b1)
Mon Apr  4 10:42:18 2016 : Auth: Login incorrect (mschap: External script says Logon failure (0xc000006d)): [Prof-PC\\Prof] (from client 192.168.1.5/255.255$
Mon Apr  4 10:42:18 2016 : Auth: Login incorrect: [Prof-PC\\Prof] (from client 192.168.1.5/255.255.255.0 port 50002 cli 00:40:d0:67:d0:b1)
Is someone know how to solve it?Thanks