Cannot connect to my home WI-FI after OTA-11 update

[Almucheck]

Phone Model: BQ E4.5
Telecom provider: O2 Germany
DSL-Modem: Alice Modem WLAN 1231
Firmware Version: 2.27-2.12.26.2u
WI-FI Mode: 802.11n
Channel: Auto
Security: WPA2 (AES)

I have updated my E4.5 to OTA-11 using my home WI-FI.
After this I made a reboot of the phone.
Then I wiped the cache partition followed by a factory reset to have a clean new system.

After another reboot I wanted to connect to my home WLAN, but it does not work. I can see the SSID in the available networks list. After insert the network password I pressed "Connect" but nothing happens.

Note: I tried 2 other WI-FI networks and there it works. I did not change anything on my home WI-FI

[Pat McGowan (pat-mcgowan)]

check to ensure the prior connections were cleared from /etc/NetworkManager/system-connections
Please attach /var/log/syslog from the time you tried to connect

[Almucheck (almucheck)]

I pressed forget prior network in the network settings (SSID name is "HAL5"). After I tried to connect to HAL5 by typing the "correct" passwort.

Phone time was around 22:30 on June 7th.

After I copied syslog (see attachment)

[Pat McGowan (pat-mcgowan)]

The log shows NM had no agent configured to provide the secrets and gave up.

Jun 7 22:26:49 ubuntu-phablet NetworkManager[1536]: <warn> [1465331209.7404] device (wlan0): No agents were available for this request.
Jun 7 22:26:49 ubuntu-phablet NetworkManager[1536]: <info> [1465331209.7406] device (wlan0): state change: need-auth -> failed (reason 'no-secrets') [60 120 7]
Jun 7 22:26:49 ubuntu-phablet NetworkManager[1536]: <warn> [1465331209.7476] device (wlan0): Activation: failed for connection 'HAL5'