As a Project Web App (PWA) administrator, you view or change the Workflow Status page or add the Workflow Status web part to a new Project Detail Page (PDP) of Type 3. When you do this, the web page content shifts to the right and leaves white space on the page. Additionally, you receive the following error message:
Sorry, something went wrong 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. For more information, contact your site administrator.
This is a known problem in Project Online. There's no current workaround. You can safely ignore this error message. This problem doesn’t affect the functionality of the web page or the workflow.