Virtual column not visible from deck view when using slice

[mmoh]

I have created a slice of my data, and tested that it was mostly accurate by clicking view dat. One of the most important columns is location_all, which is a virtual column. For every data point in this view, the column was filled out accurately.  However, when I went to create a view for this data, every entry showed this column as missing, and it was not available as an option for any of the column header in the deck or detailed format. Any idea why this is happening?