It is important to refine input files to PDF/X-1a:2001 or PDF/X-3 format first, rather than just outputting to PDF/X-1a:2001 or PDF/X-3. Prinergy Evo detects and deals with many PDF/X-1a:2001 issues during the refine stage. When you select PDF/X-1a:2001 or PDF/X-3 when outputting, Prinergy Evo software checks the master files for PDF/X-1a:2001 or PDF/X-3 conformance. However, issues such as including font embedding, image replacement, and color conversion cannot be handled at this point and will cause Prinergy Evo software to fail the file.