Network manager loses network devices

The network manager icon will indicate that it's not connected to a wireless network, and when I click on the indicator, it displays the message "no network devices available".
I cannot reliably recreate this, but it's definitely a bug since I'm filling this report while it's occuring.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: network-manager 0.9.8.8-0ubuntu34
ProcVersionSignature: Ubuntu 3.18.0-8.9-generic 3.18.1
Uname: Linux 3.18.0-8-generic x86_64
ApportVersion: 2.15.1-0ubuntu4
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Feb 4 21:26:18 2015
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2014-12-11 (56 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Alpha amd64 (20141210)
IpRoute:
 default via 192.168.88.1 dev eth0 proto static
 10.0.3.0/24 dev lxcbr0 proto kernel scope link src 10.0.3.1
 192.168.88.0/24 dev eth0 proto kernel scope link src 192.168.88.254 metric 1
 192.168.88.0/24 dev wlan0 proto kernel scope link src 192.168.88.253 metric 9
 192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
 WimaxEnabled=true
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
nmcli-con: NAME UUID TYPE TIMESTAMP TIMESTAMP-REAL AUTOCONNECT READONLY DBUS-PATH
nmcli-dev: DEVICE TYPE STATE DBUS-PATH
nmcli-nm:
 RUNNING VERSION STATE NET-ENABLED WIFI-HARDWARE WIFI WWAN-HARDWARE WWAN
 running 0.9.8.8 connected enabled enabled enabled enabled disabled