Action 'Data: set the values of some columns in this row' writes bad data to columns

[hodgson_doug]

I have an Action with ‘Data: set the values of some columns in this row’ that writes to a number of columns in my table. All the intended actions are pre-calculated using Virtual Columns so I know the testing I’ve done produces the desired result.

in one column, I use the existing column data to update it’s own contents as part of this Action:
if( CONTAINS([NOTES], [SOURCEDATA]), [NOTES], CONCATENATE([NOTES],"(OriginalData): ",[SOURCEDATA]) )

If my SourceData is already contained in the Notes column, then I just apply the existing Notes; but if not, I add it.
USING THIS SAME TECHNIQUE ON OTHER COLUMNS IN THIS ACTION RESULTS IN ERRORS. The expression editor tells me it doesn’t recognize the column and asks if I meant the exact column it says it doesn’t recognize. Yet it’ll allow it for one column near the top! Action - Expression doesn’t recognize the very column it’s updaing|690x404

[Steve]

In my experience, the error you’re getting occurs when your expression references a slice that itself does not include that column. If you’re using a slice, make sure the slice includes that column.