On Ubuntu 16.04, latest Steam beta it keeps coming up with a popup saying my credentials have changed? When they haven't.

Processor Information:
Vendor: GenuineIntel
CPU Family: 0x6
CPU Model: 0x3f
CPU Stepping: 0x2
CPU Type: 0x0
Speed: 3500 Mhz
16 logical processors
8 physical processors
HyperThreading: Supported
FCMOV: Supported
SSE2: Supported
SSE3: Supported
SSSE3: Supported
SSE4a: Unsupported
SSE41: Supported
SSE42: Supported

Network Information:
Network Speed:

Operating System Version:
Ubuntu Xenial Xerus (development branch) (64 bit)
Kernel Name: Linux
Kernel Version: 4.4.0-6-generic
X Server Vendor: The X.Org Foundation
X Server Release: 11703000
X Window Manager: Compiz
Steam Runtime Version: steam-runtime-release_2016-02-22

Video Card:
Driver: NVIDIA Corporation GeForce GTX 980 Ti/PCIe/SSE2

Driver Version:  4.5.0 NVIDIA 355.11
OpenGL Version: 4.5
Desktop Color Depth: 24 bits per pixel
Monitor Refresh Rate: 59 Hz
VendorID:  0x10de
DeviceID:  0x17c8
Number of Monitors:  1
Number of Logical Video Cards:  1
Primary Display Resolution:  3840 x 2160
Desktop Resolution: 3840 x 2160
Primary Display Size: 24.45" x 13.43"  (27.87" diag)
                                        62.1cm x 34.1cm  (70.8cm diag)
Primary Bus: PCI Express 16x
Primary VRAM: 6144 MB
Supported MSAA Modes:  2x 4x 8x 16x 

Sound card:
Audio device:

Memory:
RAM: 15946 Mb

Miscellaneous:
UI Language: English
LANG: en_GB.UTF-8
Microphone: Not set
Total Hard Disk Space Available: 204289 Mb
Largest Free Hard Disk Block: 183229 Mb

Installed software:

Recent Failure Reports: