I have googled the errors with no luck so far. I will keep looking at the logs. I wanted to post the logs and see if any one else had run into these errors. I will update this if I come up with anything else.
Double check that Javascript is enabled in your browser. Every time I forget to tell NoScript to allow my Alfresco domain, I get the blank login screen.
I have also noticed at times that Firefox needs a refresh to show the login screen.
I am facing the same issue. When I hit - http://localhost:8080/share the screen is blank. No errors in log. I am able to access http://localhost:8080/alfresco. The version in Alf 4.2.3 EE. The javascript is enabled. Not able to access from any browser - chrome, firefox, IE. Any pointers would be useful. I am upgrading from 4.1.3 to 4.2.3. The custom code is deployed successfully.