If signing in to Databook fails, the most common reason why signing into Databook could fail is that 3rd-party cookies are not enabled in your browser. as Databook's authentication process requires them to be enabled.
Here are instructions about how to change your settings in Chrome.
Go to Chrome Settings
Click on Privacy and Security from the lefthand menu
In Privacy and Security, check that:
Send a 'Do not Track' request with your browsing traffic is disabled (see screenshot)
Click on Site Settings in the Privacy and Security section
Click on Cookies and Site Data
In Cookies and Site Data, make sure that:
Allow sites to save and read cookie data is enabled
Block third-party cookies is disabled (see screenshot)