Reduce the difference to a reproducible fixture
Record the exact source bytes, selected profile, renderer or converter identity, destination application, and smallest syntax fragment that differs. Screenshots alone omit the contract needed to reproduce the issue.
Check the Markdown profile before changing syntax
A table, footnote, math expression, alert, or Mermaid fence may be plain text under another profile. Use the profile migration dry run to compare diagnostics and rendered semantics without rewriting the source.
Separate missing assets from blocked resources
A missing relative file, a case mismatch, an unsafe protocol, and a deliberately blocked remote image need different fixes. Inspect the link/image inventory and bundle manifest instead of weakening the viewer's network policy.
Match the expected fidelity to the output
Canonical PDF has a visual contract and exact proof artifact. DOCX, ODT, and EPUB preserve supported structure rather than screen pixels. Office imports are best effort and return a portable Markdown bundle with explicit losses.
Keep the report and hashes with the failure
A useful issue includes source and artifact SHA-256, the job ID, validation findings, safe error code, and relevant engine versions. Never attach tokens, signed URLs, private source, or raw converter stderr to a public report.