ggplot2 pdf import in Adobe Illustrator missing font AdobePiStd

Although changing the fonts used by AI works well, an alternative is to restrict ggplot2 from using Dingbats in the first place by adding the argument 'useDingbats' to your ggsave command eg:

ggsave(plot=p,height=6,width=6,dpi=200, filename="~/example.pdf", useDingbats=FALSE)

I ran into this problem as well on Mac OS X 10.8.2.

This resolved the issue for me:

font='/Library/Application Support/Adobe/PDFL/10.9/Fonts/AdobePiStd.otf'
cp $font /Library/Fonts/

On your system, find the file with find:

find / -name AdobePiStd.otf 2>/dev/null

/Applications/Adobe Photoshop CC 2018/Adobe Photoshop CC 2018.app/Contents/Required/PDFL/Resource/Fonts/AdobePiStd.otf
/Applications/Adobe Illustrator CC 2018/Adobe Illustrator.app/Contents/Required/PDFL Resource/Resource/Fonts/AdobePiStd.otf
/Applications/Adobe Acrobat DC/Adobe Acrobat.app/Contents/Resources/Resource/Font/AdobePiStd.otf

For dots or points that don't' display correctly in a pdf, I just substitute Zapf Dingbats for the missing font in Adobe Illustrator. For simple plot markers, this does the job most of the time.