Pivot Error - PLEASE HELP

Detlef_Lewin 

You wrote "Even more challenging considering that the first spreadsheet program VisiCalc only appeared in 1979,.

I'm not going to challenge that VisiCalc date, but I need to add to this to the conversation:  recently I was reflecting on the fact that I was creating applications (in HR of all things) using addressable multi-dimensional arrays in 1971-72 using the programming language APL, on an IBM mainframe. Check it out: https://en.wikipedia.org/wiki/APL_(programming_language)

So when spreadsheets came along I moved very easily into their models. I don't think I ever used VisiCalc per se, but did have some shareware version on my luggable Compaq at home; moved to Lotus 1-2-3 of course, at work, but also spent some years with Borland's Quattro, and eventually migrated to Excel. These days Excel is it, though I have some quick and dirty applications in Numbers (hey, I have Macs) and even Google's Sheets. Excel tops 'em all........

Just for the record, with @Joe-D78 , I recently celebrated my 78th Birthday. My grown children know they can come to me with their Excel questions, among other technical issues.....