Hello,

we have an application which uses a WinGrid with 3 bands.

On the second band we have 3 columns: Suppliers, Quantities and a third colum which uses a MultiSelect UltraCombo with the list of Orders for that supplier. After selecting the Orders by checking them on the UltraCombo it adds new rows to a third band listing the orders I choosed.

First time it works like a charm! On the BeforeCellListDropDown event I load all the orders for that specific supplier and there's no Errors.

When I pass on to another supplier it throws an Unhandled Exception like on the picture attached. The exception window appears after the BeforeCellListDropDown and not always... but 90% of the time...

It doesn't happen if I select the rows in the combo in order (from top of the list to bottom) as long as I select the first item on the list... everything else throws this error...

What could be wrong?

Please help because this project is due to deliver this week!

Many thanks.