Try exporting via the Graphics tool. Be sure to specify PDF as the output format, and not one of the graphics.

You can't blame Finale for functionality missing from the operating system. Unlike the MacOS, Windows 8 does not have a native PDF printer and never did. Disappointing as that may be, you need to install a 3rd party PDF printer. I'm sure that others may have a suggestion for you.

https://www.makeuseof.com/tag/how-to-print-to-pdf-from-windows-8-desktop-modern-apps/ 

Win10 did come with a native app, Microsoft Print to PDF, but Microsoft removed it in a later update. Here's how to get it back.

https://answers.microsoft.com/en-us/windows/forum/all/where-can-i-get-microsoft-print-to-pdf/367f6ea3-64cd-4398-8f53-1da9029d8357 

Many people have complained about printing or exporting to PDF from Finale. It appears the best way is to print to a virtual PDF printer such as Cute PDF or PDF Creator, which I have used for a long time without any problems, printing to any page size. Make sure that at the first Print Dialog you have checked Fit to page, then go to Setup to choose the Printer, sizes, pages, etc.

Thank you all for your responses. The Graphics Tool did not give me an option to export as a PDF. It only gave me the option to export as PNG, JPEG, SVG, or TIFF.

The Cute PDF virtual PDF printer option worked for me.

It just seems rather odd that a $600 music notation software can't easily export as a PDF. I shouldn't have to jump through 20 hoops just to export as a PDF. MuseScore (a free notation software), exports to PDF no problem with one click. 

Thanks again for the help.

What's odd is you not understand that, if the operating system doesn't support a function, it's unavailable to any application. I gave you a link that explained this in greater detail.

Once again: Win 8 does not have the ability to save or print to pdf without a 3rd party driver. As you have found, Cute PDF gives you this functionality—as do many other 3rd party drivers.

I'm not here to argue, but in your case, I'll make an exception. If you read my last post, I explained that MuseScore (which I also used on Windows 8.1), easily exported to PDF with one click. No problems whatsoever. I am saying that a $600 music notation software (Finale) should be able to do the same. Why is a free music notation software like MuseScore able to do it and not Finale, on the same exact operating system? I am merely pointing this out to draw attention to this issue, so that the developers of Finale can fix this in the future. 

Also, consider learning English. Read your first sentence. That's basic grammar that should have been learned in third grade.

A missed gerund is no excuse for insulting a longtime user and forum participant.

From the user manual:

I'm not here to argue,…

Apparently, you are. This forum is for Finale users helping other Finale users. Why something might work in MuseScore is not our concern. (Ok, I do know the answer but I'll let you search the MuseScore forums for it).

Please note that, when you followed my instruction and installed a 3rd party pdf tool, your problem was solved.

You're welcome.