A client reported the following error:
"To save this file, you must select a visible sheet."
from _UExcelRecords.TWorkbook (TWorkbook.FixSheetVisible)
This fired when a FlexCel file object was saved to a memory stream. The file, which I don't have access to, contained data to be imported into the application. Any idea what the problem is? How can I check and avoid this in future?
This problem normally means what it says: The xls.ActiveSheet is not a visible sheet. This would create a file that would crash Excel.
You can check if the selected file is visible by checking:
if (xls.SheetVisible <> TXlsSheetVisible.Visible) then...
And then you can select a valid sheet by setting xls.ActiveSheet := sheet;
Probably you can make a loop and select the first visible sheet in order to save. But the sheet you select is the sheet that will be selected when you open the file in Excel.