...
The first time Box Sync launches you will see a prompt like the one below. You first need to click on Use Single Sign On (SSO).
Once the prompt changes to the way the picture looks below, enter in your email address and click Log In.
You will be taken to an EID login prompt. Enter your EID credentials and click LOG IN.
After approximately 30 seconds a Box Sync window will reappear. Click Start Syncing.
...