Your films can show a PostScript Error. PostScript is the complex printing language owned by Adobe. PostScript Errors inform the user something is wrong in the file. You can google a PostScript Error to gain some insight.
1. Build clean art files. Most errors derive from vector files that were over developed (too many anchor points/nodes) Auto-traced incorrectly can lead to an issue.
2. Fonts that are non Adobe fonts may cause an error. Converting fonts to curves/outlines can often solve the issue.
3. Print properly by using the RIP as it was designed. Taking a finished spot color file with different colors and manually moving elements off the page and turning the color on the document to black is NOT how you separate a file. In addition to be slow and likely to cause a human error, a PostScript Error can occur. Also, these manual separators then print the file as a COMPOSITE and not as a Host-Based Separation.
4. Print using the SEPARATION feature even for one color jobs and even one color jobs with the elements colored 100% black.
5. If your graphics program has the built in ability to RASTERIZE data before printing this will also help eliminate PS Errors. Print at 400 dpi or higher for better results.