Run created report from video "how do i build a document report in nav2013"

After preview in Role Center, it displays

"An error occurred during local report processing.
The Hidden expression used in text box ‘Quantity_SalesInvoiceLine’ returned a data type that is not valid.
The Hidden expression used in text box ‘Quantity_SalesInvoiceLine’ returned a data type that is not valid. "

I need your help, thanks.

Go to the Textbox and open properties an go to visibility property and see the code written. it look like there datatype mismatch. Please check it,

I added ‘Quantity_SalesInvoiceLineFormat’ under Visibility property and I have removed it. It working now but my output is not in accordance with my layout. Thank you.

Report ErrorS.png

ReportError2B.png

ReportLayoutB.png

My displays are not in accordance with layout.

I need your help, thanks.