A PostScript error ‘undefined’ offending command ‘havefont’ can be caused by problems with fonts in an Illustrator file (according to Morten from Scandinavia who was kind enough to e-mail this).
Solutions
- Create an outline of the font in Illustrator.
- Morton thinks his problem was caused by saving an Illustrator 7/8 file as Illustrator 6. Maybe resaving in another version can also solve the problem.
- Fred Gamber was kind enough to mail the following advice: My experience indicates that a corrupt font supplied by a customer is to blame in about 3/4 of the cases we run into. If you replace the screen and printer fonts with versions you know to work, the problem usually goes away. This can be a faster method than trying to isolate an Illustrator file in a job with large amounts of those files included.