I've been receiving the above exception on my grids when they're initially filled with their first page of data and on first call to BestFitColumns.
When tracing into decompiled source, the error is thrown on the function in StretchVirtualGridColumnLayout.cs
stretchableColumns are null at this moment which is what's throwing the exception.
Investigating further by placing some break points, the above function is being called before the function "public override void CalculateColumnWidths(SizeF availableSize)" which actually generates the stretchableColumns list.
Im sorry, but I can't include a sample project at this time as the code is too complex.
The grid.OnCellValueNeeded event drives obtaining the data.
I'm not sure where I should call the BestFitColumns method. I am receiving the exception in the OnCellNeeded and OnCellFormatting events on the first call.
Can you advise please?