@ShaziaN there's an infrastructure related issue:

CURRENT STATUS

Developer Site: Available
New PDI provisioning: Paused
PDI reclaim and wake actions: Paused
Existing PDIs: Some are offline
Developer action: No action is required at this time

Read this Incident: Developer Site Restored and PDI Availability Issues for more details.

@BobMullinea have you been logging in as an explicit login via https://yourPDI.service-now.com/login.do and inserting your user name and password?

Accessing your instance from the Developer portal by clicking Start building doesn't count as activity...