What could be causing my MacBook Air 13inch (Mid 2012) 2 GHz Intel Core i7 OS X 10.8.4 to throw the "could not join" WiFi error? For some reason, my MacBook Air 13inch (Mid 2012) 2 GHz Intel Core i7 OS X 10.8.4 will fail to connect to my Siemens SE567 ADSL Modem when WiFi security is enabled on it. It throws the following error message:



Every other device in the house will connect which includes:


An older MacBook Air
2013 Mac Mini
2 iPhone 5s
iPad Mini
iPad 1st gen
And an Apple TV


I've played around with all the settings, deleted network profiles, plists, reset the p ram and still get the error. Error only occurs when WiFi has security enabled.

Some more info about my system's WiFi:

Software Versions:
  CoreWLAN: 3.3 (330.15)
  CoreWLANKit:  2.0.2 (202.10)
  Menu Extra:   8.1 (810.9)
  configd plug-in:  8.4 (840.22.1)
  System Information:   8.3 (830.5)
  IO80211 Family:   5.3 (530.4)
  Diagnostics:  2.0 (200.24)
  AirPort Utility:  6.3.1 (631.4)
  Interfaces:
en0:
  Card Type:    AirPort Extreme  (0x14E4, 0xE9)
  Firmware Version: Broadcom BCM43xx 1.0 (5.106.98.100.17)
  MAC Address:  94:94:26:00:29:d0
  Locale:   FCC
  Country Code: X0
  Supported PHY Modes:  802.11 a/b/g/n
  Supported Channels:   1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 36, 40, 44, 48, 52, 56, 60, 64, 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140, 149, 153, 157, 161, 165
  Wake On Wireless: Supported
  AirDrop:  Supported
  Status:   Connected
  Current Network Information:
Wifi:
  PHY Mode: 802.11g
  BSSID:    c0:d0:44:54:50:20
  Channel:  11
  Country Code: X0
  Network Type: Infrastructure
  Security: WPA Personal
  Signal / Noise:   -41 dBm / -92 dBm
  Transmit Rate:    54
  Other Local Wi-Fi Networks:
The fastnet:
  PHY Mode: 802.11g
  BSSID:    80:a1:d7:31:f1:b1
  Channel:  6
  Network Type: Infrastructure
  Security: WPA/WPA2 Personal
  Signal / Noise:   -86 dBm / -92 dBm
I have done some in depth analysis for the same error on my MBA.

Basically there seems to be a MBA software problem somewhere in the Airport application.

In my case it looses the last digit of the Network Name (SSID) and then it claims it can not find it (what a surprise).

Then it issues the generic Connection time out Error.

Here is what it looks in my Console:



The actual name is Eurona900850808-81
as shown in the WiFi scan.

I would check the Console report on your computer to see what is going on.

If you need help how to get the report on your computer let me know.

I have been able to partially overcome this issue by disabling the Auto Join, and Auto remember networks.