EPUB FixerKDP upload error scanner

EPUB error guide

Kindle Previewer conversion failed

Scan the EPUB that Kindle Previewer could not process when conversion fails, enhanced typesetting stops, or Previewer reports validation, TOC, metadata, link, anchor, or package problems.

Scan EPUB structureSee an example report

Best fit

Previewer failed on a reflowable EPUB.

Upload the same EPUB that failed so the report can map the Previewer wording to OPF, nav.xhtml, toc.ncx, links, anchors, manifest, media type, or ZIP packaging.

Report shows

Whether another Previewer retry is worth it.

A checked repair is only useful after the fixed EPUB passes EPUBCheck again; otherwise the report should name the manual source or EPUB editor task.

Not this scan

KPF, DOCX, PDF, cover, or account problems.

Use Kindle Create, the source export, KDP workflow, or support when the failure is not inside the EPUB package.

Scan the EPUB to check file paths and see what can be repaired or needs manual review. Your original EPUB stays unchanged.

No signup before the scan report.Your original file is not overwritten.Repair download only after EPUBCheck passes again.

Need fixed-layout, DRM, or source-file help? Check unsupported or review-first EPUB cases.

Match these report titles

  • Kindle Previewer failed
  • Kindle Previewer conversion failed
  • Enhanced typesetting failed
  • Kindle Previewer EPUB validation error

Start here

Save the Previewer wording before re-exporting.

Kindle Previewer can fail for broad reasons. If the input is an EPUB, scan that same file to see whether the failure maps to package structure, TOC/navigation, metadata, links, anchors, manifest, or ZIP packaging.

Matched

What it means

Kindle Previewer converts and checks the manuscript before KDP publication. When the input is EPUB, failures can come from strict EPUB package problems.

Matched

Can it be fixed automatically?

A checked repair is possible when the Previewer failure maps to one clear EPUB structure fix that can be checked with EPUBCheck again before another Previewer run.

Matched

What to check next

Save the exact Kindle Previewer message before re-exporting.

Matched

What not to assume

It cannot solve Kindle Create bugs, KPF issues, DOCX/PDF import behavior, account problems, cover workflow, fixed-layout design, or visual formatting decisions.

1. Example report output

What a Previewer failure report should show.

A useful report should turn the Previewer symptom into a specific EPUB check.

Previewer wording

Conversion failed, validation error, missing TOC, enhanced typesetting failed, or upload could not process.

EPUB area

Package metadata, nav.xhtml, toc.ncx, OPF manifest, XHTML link, CSS path, image path, anchor, or ZIP wrapper.

Related EPUBCheck

RSC, OPF, NCX, or PKG messages if the same file is checked with EPUBCheck.

Decision

Checked repair, manual EPUB editor/source review, or unsupported.

The report should tell you whether another Previewer retry is worth doing or whether the source export needs work first.

2. Next step

Choose the next step from the Previewer failure.

The same Previewer message can map to different EPUB layers.

Upload scan

Use this when Previewer fails on an EPUB.

Scan the exact EPUB that failed so the report can locate the package, metadata, navigation, link, or ZIP blocker.

Checked repair

Use this when one structure fix is clear.

After repair, reopen the fixed EPUB in Kindle Previewer only after it passes EPUBCheck again.

Source review

Use this when formatting or layout is actually wrong.

Return to the source tool when the failure depends on visual layout, missing content, fixed-layout design, or reader presentation.

3. Concrete path example

A Previewer failure can hide a TOC wiring issue.

The visible Previewer symptom may not name content.opf, but the package path still matters.

Previewer:
Conversion failed. Check the EPUB for errors.

Report:
Found: OEBPS/nav.xhtml
Problem: nav.xhtml is not marked with properties="nav" in content.opf
Decision: repair only if nav.xhtml is the intended EPUB 3 table of contents
Next: run EPUBCheck again, then reopen in Kindle Previewer

If Previewer fails because the book layout itself is wrong, fix the source workflow rather than patching package files.

Quick decision

Decide whether Previewer failed on structure or presentation.

Previewer failures belong here only when the input is a reflowable EPUB and the problem maps to package structure.

Good fit

Previewer failed while processing an EPUB.

The scanner can inspect structure blockers that often cause conversion or validation failures.

Manual fit

Previewer shows broken TOC, links, or layout after conversion.

The report can locate structure issues, but source formatting or layout may still need manual work.

Not this tool

Previewer failed for KPF, DOCX, PDF, cover, account, or service problems.

Use Kindle Create, source export, KDP support, or the relevant workflow instead.

Common situations

Common Kindle Previewer failure cases.

Start from the failure wording and whether the input file is a reflowable EPUB.

Matched

Previewer says conversion failed.

The failure may come from a package, metadata, navigation, link, or ZIP blocker.

Scan the EPUB and use the first affected path before another export.

Matched

Previewer opens but the TOC or Go To menu is broken.

The EPUB may have chapter files but disconnected nav.xhtml, toc.ncx, or OPF spine wiring.

Check the navigation layer before rebuilding the whole book.

Matched

Previewer reports EPUB validation errors.

The wording may differ from raw EPUBCheck, but the same internal path can be involved.

Keep the Previewer message and compare it with the scan report.

Kindle Previewer conversion failed phrases to check

Kindle Previewer failed: conversion failed, enhanced typesetting failed, EPUB validation error, missing TOC, metadata, package, link, anchor, manifest, or ZIP blocker.

Where Kindle Previewer failures appear

Kindle Previewer cannot process an EPUB, reports conversion failure, shows validation errors, misses the table of contents, or fails before a KDP upload retry.

What it means

Previewer failures can come from EPUB structure, not only visual formatting.

Common causes include broken navigation, missing TOC wiring, wrong OPF metadata, missing manifest entries, stale links, missing anchors, missing images, wrong media types, container.xml problems, and bad ZIP packaging.

Before you edit

Check the EPUB package behind the Previewer error.

Do not keep exporting the book blindly. First find whether the Previewer failure has an EPUBCheck-style blocker or a named package path.

  1. 1Save the exact Kindle Previewer message before re-exporting.
  2. 2Confirm the failing input is a reflowable EPUB file.
  3. 3Scan the EPUB and check whether the report names package, metadata, navigation, link, anchor, manifest, media type, container, or ZIP issues.
  4. 4If a repaired EPUB is produced, open it in Kindle Previewer only after it passes EPUBCheck again.
  5. 5Return to the source workflow when the issue is visual layout, missing content, fixed-layout design, or file conversion.
  6. 6Do not treat KPF, DOCX, PDF, cover, paperback, or account problems as EPUB structure repair.

Why KDP checks it

Why Previewer and EPUBCheck overlap.

KDP eBook file formats

KDP supports EPUB files that meet Kindle Publishing Guidelines and recommends checking the file with Kindle Previewer before upload.

EPUBCheck

EPUBCheck checks EPUB 2 and EPUB 3 files against the official rules and reports package, markup, link, and file-reference problems.

EPUB 3.3 package rules

The OPF file is the EPUB's map: metadata, file list, reading order, and navigation wiring. KDP and EPUBCheck use it to decide whether the book package is coherent.

Repair example

When a Previewer failure can be repaired here.

Before / after example

Before: Previewer conversion fails and the scan finds nav.xhtml is present but not declared in content.opf. After: align the OPF nav property only when that file is the real TOC and EPUBCheck passes again.

Ready to retry?

Scan the EPUB that failed conversion in Kindle Previewer.

Use the exported EPUB that Previewer could not process. The report shows whether a checked repair is possible before another Previewer run.

Upload EPUB to scan

FAQ

Questions authors ask when Kindle Previewer conversion fails.

Why did Kindle Previewer fail on my EPUB?

It may have found an EPUB package, navigation, metadata, link, anchor, manifest, media-type, or ZIP problem. Scan the EPUB to find the affected path before exporting again.

Is a Kindle Previewer failure the same as an EPUBCheck error?

Not always, but they can overlap. EPUBCheck-style structure problems often explain Previewer validation or conversion failures.

Should I re-export before scanning?

If you still have the EPUB that failed, scan it first. The report can tell you whether another export is needed or whether a clear package fix exists.

Can EPUB Fixer fix enhanced typesetting failures?

Only if the failure maps to a clear EPUB structure blocker. Visual layout, source formatting, and Kindle-specific rendering issues are outside this scanner.

Related EPUB error guides