I have two users that have the same issue with fonts changing when being saved as a PDF and when compiling multiple files into one pdf book. One of the users has was not able to save or print a file to Adobe DC without the font causing an issue. He could however Print to Cute PDF without issue, but in doing so, he was then not able to compile that book since one of the files was made with CutePDF.
Is there a simple solution that I am missing, where additional fonts need to be installed? Could this be a single "shared" pdf document that is the cause of the issue?
The font change issue happens when FM has to change from the default system printer to the Adobe PDF printer instance for creating the temporary postcript for distilling. The internal fonts of the devices are different, so FM issues a warning that the available fonts have changed. What can be a real problem is if the documents are using a printer font from the current system device (not a recommended practice in any circumstances).
Adddendum: Also, when creating a PDF froma book file, open all files in the book first to ensure that there are no [font, cross-ref, etc.] issues, otherwise if the files aren't open, then during FM's silent opening when creating output, any errors or warnings on opening will cause the print job to fail.