There can be multiple reasons why authentications to the SaaS applications (Google Apps, Salesforce, and Office 365) fail.
Time Synchronization: CloudAccess depends on timestamps to function correctly. Synchronize time between the VMware or Hyper-V host server, the appliance, and the workstations. Download the authentication or single sign-on logs. In the catalina.out file, search for the error clock skew.
SAML Authentications: Firefox contains a SAML debug add-on you can use to view the SAML authentication between CloudAccess and the SaaS applications. Download the add-on SAML tracer to view the SAML request.
Master Node Down: If the master node is not running, users who already have accounts can log in to SaaS applications, but CloudAccess cannot provision new users. So, if new users attempt to log in to SaaS applications and receive an error indicating they should contact their system administrator, verify that the master node is running.