Created Issue: Hangs on inserting row [8664]

When I try to run the code for the file attached

using (var workbook = new XLWorkbook("x.xlsx')) {
var worksheet = workbook.Worksheet("Vendors");
worksheet.RowsUsed().First().InsertRowsAbove(1);
....

it hangs on the 3rd row.


(Some rows/columns were deleted from Vendors sheet using Excel.)

Any help would be appreciated!

Thanks,
Skaidrius.