This can be the result of having no data source set and so Refresh Data cannot pull the data through. To set the data source:
On the right of the data source area, click the edit pencil icon.
Select your Dimensions data source.
If your database appears, select the database.
Click Save.
Your page will reload, and you may need to specify your obligation again after which you can click Refresh Data which should now populate the central area with the required VAT figures.