WildWestDesigns
Active Member
EPS from newer versions of CC are not backwardly compatible to older versions of illustrator. The only way I've found to solve this reliably is to run the file through InDesign. Create a blank document, place the EPS, and then export to a compliant PDF. Works every time.
That's always been the case if the default EPS version is used. They would have to have selected a legacy EPS option.
Downside is if they had used any new features that Ai has that aren't supported in those old versions. Sometimes there are workarounds. I remember when gradients on strokes first came out, I had to outline the stroke before saving as EPS. Something along those lines.
Unless they (Adobe) has removed legacy EPS exporting from newer versions of CC, then that's something else entirely.