Is it possible that it does not make a diagonal line when converting to pdf ?
When I convert from mathcad to PDF, I got this diagonal line !
My question is can I do something so the diagonal line there when I convert to PDF !??
Look in the Mathcad file and look after at the PDF!
The problem here is not Prime but the pdf printer you are using.
I can confirm that when I "print" via "Microsoft Print to PDF" I get the diagonal, too.
Using another pdf printer (like Adobe PDF) the problem does not show up.
So the solution is to use a different pdf printer to create the pdf file. There are also a lot of free ones out there (CutePDF, PDF Creator,...).
You may also consider to save the file in rtf or xps format from within Prime and then print it to a pdf.
EDIT: I just gave it a try. When I save it to rtf (from within Prime) and print it from within M$ Word using the Microsoft Print to PDF printer, I get no diagonal. So this may be a solution to your problem if you don't want to install another pdf printer.
When I save the file to xps and print it from within the XPS viewer with the M$ printer, I still get the diagonal.
I created a similar file (empty area on an empty sheet) in Prime 4 and printed it with Microsoft Print2pdf and it did not produce a diagonal...
Difference may be Prime version (5 versus 4) or bitness (64 for Prime 5, 32 for Prime 4) or ...
It look like its the combination of Prime 5 and the M$ pdf printer which is responsible for the problem.
I added a full line text region to your file as is in the OP's file and printed it from within Prime4 without problems.
After saving the file and opening it with Prime 5, the diagonal was there when printed with M$ pdf.
I guess that switching from Prime 5 to Prime 4 is no option for the OP.
So the possible solutions still are:
1) install and use a different pdf printer
2) Save to RTF, open in Word and print from there.