You have a font issue. The font needed is probably not installed so the PDF maker doesn't know what to use.

Are you using a PDF printer utility? I use doPDF and CutePDF. I understand Mac's have there own and since I am not a Mac user one of our good Mac people can help you better with it than I.

I am a Mac user, and I don't use Finale's built-in export, either. I use the Graphics tool > Export Pages > as PDF.

I don't use Finale's built in Export to PDF and I don't know why because every time I have used it, it worked perfectly.

I have just always used doPDF or CutePDF.  I guess because most apps don't print to PDF by themselves.

I just tried my latest score using Finale's Export to PDF and it looks fine.

Does your PDF Print Routine give you the option to embed fonts in your PDF?

Does your computer have the actual font file or only the screen version?

You need to install the fonts so that they are available to all applications. This is easy on a Mac but I need some info. Are you using the Finale fonts or third party? Are you really running 25.5 or another build of Finale? What is your macOS? There used to be a link but it no longer works—that’s ok but it would have saved some time.

Same thing happens when I export from Graphics. Plus, printing to pdf from the print dialog automatically saves it with the part in the file name. Graphics wouldn't do that. 

I'm using all Finale fonts. And yes I'm actually running Finale 25.5 on Sonoma 14.0.

My print routine doesn't give me the option to embed fonts.  

… I'm actually running Finale 25.5 on Sonoma 14.0 …

Finale 25.5 is not supported on Sonoma (= you will probably face many problems).

Consider upgrading Finale, or downgrading Mac OS.

The current build of Sonoma is 14.1.1 and is a major bug fix so you want to run that update first.

Downgrading Sonoma to Ventura is easy. To Monterey or earlier should only be done with Apple Support on the phone.

Finale has an upgrade sale going on today and tomorrow, you should take advantage of that. 

https://www.finalemusic.com/finale35/?utm_source=Iterable&utm_medium=email&utm_campaign=campaign_8304358 

Use promo code FINALE35 at checkout!

You won't get the Sonoma compatible 27.4 till it's available but we've been promised that soon — and you will be entitled to MM Tech Support when you do. 

In the meantime, the way that MM installs fonts in 27 is different than it was in 25. I still know the old way to make the fonts available to all applications but am not confident that still works over Sonoma. If you upgrade to 27, you won't need it.

I think something was wrong with the file. I ended up creating a new drum part from scratch and that seemed to fix it. I also upgraded my version of Finale. 

Entirely possible.

By the way, the Sonoma compatible, Finale 27.4 build dropped yesterday. The Finale upgrade sale that I linked is still good but ends tomorrow, December 1, 2023.