Comment 69 for bug 1320070

my machin is thinkpad-E550 and #48 worked for me.
uname -a
Linux ThinkPad 3.19.0-25-generic #26~14.04.1-Ubuntu SMP Fri Jul 24 21:16:20 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

BUT MODULE VERIFICATION FAILED! signature is not validu!??? please explain what should i do?

$ dmesg | grep rtl
[ 10.250033] rtlwifi: module verification failed: signature and/or required key missing - tainting kernel
[ 10.510565] Using firmware rtlwifi/rtl8723befw.bin
[ 10.513766] ieee80211 phy0: Selected rate control algorithm 'rtl_rc'
[ 10.514272] rtlwifi: wireless switch is on

lspci -v

u04:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8723BE PCIe Wireless Network Adapter
 Subsystem: Lenovo Device b736
 Flags: bus master, fast devsel, latency 0, IRQ 18
 I/O ports at 4000 [size=256]
 Memory at f1200000 (64-bit, non-prefetchable) [size=16K]
 Capabilities: [40] Power Management version 3
 Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit+
 Capabilities: [70] Express Endpoint, MSI 00
 Capabilities: [100] Advanced Error Reporting
 Capabilities: [140] Device Serial Number 00-23-b7-fe-ff-4c-e0-00
 Capabilities: [150] Latency Tolerance Reporting
 Capabilities: [158] L1 PM Substates
 Kernel driver in use: rtl8723be