Value error when using lookup with a pivot table

Hi

I have a report i am trying to compile from a pivot table.

In the attached spreadsheet i have a Data input sheet, a return sheet and the pivot table. You can see from the workbook that cell D9 on the Group return sheet returns an error. I think it is a format issue or that the pivot table is reading a formula. Column M on the data input sheet is a formula to add the text 'Age' to an age formula

All help gratefully appreciated

Thanks

Andy