OnCommand Workflow Automation server is unavailable with error '404 not found'

Applies to

OnCommand Workflow Automation(WFA) 5.0

Issue

• Unable to access Workflow Automation GUI, getting 404 not found error on the browser. 
• Services are in Running state.
• Current status of deployment file extension is 'failed'.

Log Error:

ERROR [org.jboss.msc.service.fail] (ServerService Thread Pool -- 37) MSC000001: Failed to start service jboss.persistenceunit."wfa-0.5.ear/workflow 0.5.jar#wfa-workflow": org.jboss.msc.service.StartException in service jboss.persistenceunit."wfa-0.5.ear/workflow-0.5.jar#wfa-workflow": javax.persistence.PersistenceException: [PersistenceUnit: wfa-workflow] Unable to build Hibernate SessionFactory