Odoo 9 screen is blank

Issue: 

Solution:

I have found discussion on https://github.com/odoo/odoo/issues/19627 , seems that this issue was known. I tried the workaround to delete the assets information belong in /web/content

DELETE FROM ir_attachment WHERE url LIKE '/web/content/%';

but the first try wasn't successful, so i tried restart the service and refresh my browser.

Still not okay the second, third ... etc. I can't remember how many times i tried but at last it worked.

It's weird but I'm happy as for now. Eureka!