UserAgent: Mozilla/5.0 (X11; CrOS x86_64 9202.56.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.123 Safari/537.36

Steps to reproduce the problem:
1. log in as user
2. press enter
3. black screen

What is the expected behavior?
(normal login)
Details:

Google Chrome OS

Version 57.0.2987.123 (64-bit)
Platform 9202.56.1 (Official Build) stable-channel falco
Firmware Google_Falco.4389.92.0

What went wrong?
blank screen, works as a guest to my primary email(login account) .I have updated to no effect. I believe that ver. 56 has a similar problem. I cannot powerwash as I am a guest and this is greyed out.

Did this work before? N/A 

Chrome version: 57.0.2987.123  Channel: stable
OS Version: 9202.56.1
Flash Version: Shockwave Flash 25.0 r0

I happened suddenly 2 days ago after years of solid service.
Really need this machine to be up and running, Help appreciated.