Project Online 'Submit' button is greyed out and the workflow is stuck at processing stage.

It seems like the workflow doesn't work anymore. I have tried modifying the workflow to change from a stage to another by publishing a project as the workflow below. After I published the workflow and tested. Once I published the project, the stage doesn't change. Not sure if I miss setting up something in Project. I've activated in Site Settings as below:

Site Collection Administration > Site Collection Features 
1)    SharePoint Server Publishing Infrastructure
2)    SharePoint 2007 Workflows
3)    Publishing Approval Workflow
4)    Workflow
Site Actions  > Manage Site Features 
1)    Project Proposal Workflow
2)    Project Web App Connectivity