No connection to WPA-Wifi with 64 char ascii password

[Brodrian]

It's not possible to connect to a WPA2-PSK WiFi using a 64 character long Password. Neither in the network-managment nor in the Prompt (the save/connect button is greyed out). The 802.11i reson which is always quoted doesn't seem legit to me, since the exact same setup (& PW) worked with mint15 & 17.1 (on the same laptop), Android devices and Windows.

Important INFORMATION: The WiFi I'm connected in the Bug Report (and obviously on the Screenshot) is not the one with the 64 char password. It's my mobile-phone-hotspot.

Thanks for your effort and best regards
Brodrian

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: network-manager-gnome 0.9.8.8-0ubuntu4.3
ProcVersionSignature: Ubuntu 3.16.0-30.40~14.04.1-generic 3.16.7-ckt3
Uname: Linux 3.16.0-30-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.7
Architecture: amd64
CurrentDesktop: Unity
Date: Thu Apr 9 23:46:00 2015
ExecutablePath: /usr/bin/nm-connection-editor
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2015-04-09 (0 days ago)
InstallationMedia: Ubuntu 14.04.2 LTS "Trusty Tahr" - Release amd64 (20150218.1)
IpRoute:
 default via 192.168.43.1 dev wlan0 proto static
 192.168.43.0/24 dev wlan0 proto kernel scope link src 192.168.43.182 metric 9
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
 WimaxEnabled=true
SourcePackage: network-manager-applet
UpgradeStatus: No upgrade log present (probably fresh install)
nmcli-con:
 NAME UUID TYPE TIMESTAMP TIMESTAMP-REAL AUTOCONNECT READONLY DBUS-PATH
 Wired connection 1 b0fe5631-8d56-4fee-b204-a1d43d0af3f2 802-3-ethernet 1428579556 Don 09 Apr 2015 13:39:16 CEST yes no /org/freedesktop/NetworkManager/Settings/2
 Chang Jiang 04cd89d7-c578-489d-b1eb-edb8fd711155 802-11-wireless 0 never yes no /org/freedesktop/NetworkManager/Settings/1
 G² 96b94f2a-bc0d-448e-9c39-7da9df16d792 802-11-wireless 1428615785 Don 09 Apr 2015 23:43:05 CEST yes no /org/freedesktop/NetworkManager/Settings/0
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH
 eth0 802-3-ethernet unavailable /org/freedesktop/NetworkManager/Devices/1
 wlan0 802-11-wireless connected /org/freedesktop/NetworkManager/Devices/0
nmcli-nm:
 RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN
 running 0.9.8.8 connected enabled enabled enabled enabled enabled