The PowerPivot management dashboard does not show all usage data like it is suppose to and you see that the PowerPivot Management Dashboard Processing Timer Job fails.
You may see errors like:
"Call to Excel Services returned an error"
“Cannot query internal supporting structures for column 'Date'[Rolling52Weeks] because they depend on a column, relationship, or measure that is not processed. Please refresh or recalculate the model”
The error information can be generic and not very useful for this issue. You can verify this specific issue by starting SQL Server Management Studio and pointing it to your PowerPivot Service Application database, it is likely on the same SQL Server as you SharePoint 2013 content databases. The database will likely be named something like this "DefaultPowerPivotServiceApplicationDB-57bc03ae-bd41-4102-ab6f-f03201e3b583"
Expand the database in the tree and expand the Views folder.
Right click on Usage.vDate and pick "Select top 1000 rows"
Scroll all the way to the right in the results grid and look at the values for the "Today" column.
If the "Today" column has NULL in it this is our problem (the column should have a valid date in it)
Open a new query window to the PowerPivot Service application database (same as referenced in the above steps)
Run this command:
EXECUTE sp_refreshview N'Usage.vDate';
This issue was caused because the table the view references has been modified and the view was put into an invalid state.
I am working with the product group to have SQL updates refresh these views automatically.