An unexpected error has occurred. Web Parts Maintenance Page: If you have permission, you can use this page to temporarily close Web Parts or remove personal settings. PWA login issue only resolved when Farm Owner account logs in.

All non-farm owners of PWA receive following message at beginning of the business day when attempting to log in.

"An unexpected error has occurred.

Web Parts Maintenance Page:  If you have permission, you can use this page to temporarily close Web Parts or remove personl settings.  For more information, contact your site administrator.  Troubleshoot issues with Windows SharePoint Services."

The farm was configured with a user LDAP account instead of a application LDAP account.  This user assigned himself as the System account in SharePoint.  This same user has a non-administrative account in Project Server.  The user has a network login established automatically when he opens PWA and doesn't see the user-password login screen.  Once this farm owner establishes his PWA session in the morning, all other users can then access PWA. 

The installation owner also did not chose unique accounts for other services as recommended as best practice including (Microsoft Project Server Events Service, Microsoft Project Server Queue Service, SharePoint - 80 (Application Pool)).