PowerPivot: Can't add slicer to Pivot Table

I've got a Pivot Table that is pulling data from PowerPivot and for some reason it won't insert a slicer. I select the slicer I want and when I click OK, nothing happens. I've checked the data source and everything seems to be working fine. One other thing to note. If I have an old slicer and I try to connect it to my new Pivot Table, I get the following error: "This PivotTable report is invalid. Try Refreshing the data."

Any thoughts?

Try going in to PowerPivot data model and refresh connection to source.

Ensure Slicer column is in there and has valid values.

I assume slicer is either a column within same table or related table within the model.

Sounds like data model changed from when old slicer was created and tool is unable to make connection to new pivottable.