An error message is displayed when you click the Save button after uploading a document to the Project Deliverables document library via the Upload Document button and you cannot save the item.
This also means that if you have updated the properties of the new item your changes are not savable.
This is due to SharePoint behavior. You can close the dialog and the document will still be uploaded to the Project Deliverables document library.
You can update the item's properties by selecting Edit Properties from the item menu.