Could there be a repeating field set to slide up in one of these layouts?
There's a known issue for that.
I also seem to recall previous reports of problems when saving a PDF with a very large number of pages, but a search of the Known Bugs List Database isn't pulling up any matches for me...
If you view one of the 5000 records, does it crash when you save as PDF?
If you view 10 records, does it crash? You see where I am going here...
If it crashes with 1 record, I would suspect a damaged layout or index.
If it crashes when over 3024 records, it is probably something else.
If I choose print and select the Adobe PDF printer I can see the page count go to about 417 and then Filemaker crashes. I set the print pages to go from 1-200 and it printed that range fine. It seems it has something to do with the large file size. I did print pages 400 to the end of the document which was 471 and it saved to a pdf fine for that as well.
Unlikely, but possible things.
The printer driver is out of date, or inadequate (badly programmed)
Your computer has minimal RAM, the second DIMM in your (2?) DIMM RAM install is broken, incompatible, or something.
You hard drive is chock full and can not provide temporary memory space for PDF calculations.
RAM would be my first suspicion.
You may also want to report this in Report an Issue so that the FileMaker Techs that monitor that section can check their DB system for possible issues for you to check to see if they might be a factor.