Hi,
I have added a document column to a view and used the preview component to make it show. The preview didn’t show however, while it was the only document column in the view. This view has 40 columns where the new document column was the last in line. I moved the column up in the subject to find out if this might solve it, but it didn’t. Then I moved the column up in the model itself (to the fifth position) and this gave the expected result.
So my question is if there is a max number of columns that is checked if it contains a document column (and if so, how many) or was this just by chance and is something else the reason the preview didn't show?