EPUB FixerKDP upload error scanner

EPUB error guide

Check EPUB after InDesign export

Scan an InDesign reflowable EPUB to check generated XHTML, CSS, image paths, TOC wiring, OPF entries, media types, and ZIP packaging before upload.

Scan EPUB structureSee an example report

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

  • Check EPUB after InDesign export
  • InDesign EPUB failed validation
  • InDesign EPUB failed KDP upload
  • InDesign EPUB image, CSS, TOC, OPF, manifest, or ZIP blocker
  • Validate InDesign EPUB before Kindle upload

Start here

Check the InDesign EPUB package before editing layout files.

Upload the reflowable .epub InDesign exported, not the .indd file. The scan checks generated XHTML, CSS, images, fonts, OPF entries, navigation files, and ZIP packaging before you edit styles or export settings.

Matched

What it means

InDesign source layout and EPUB output are different artifacts. Validators inspect the exported package: generated XHTML, CSS, assets, OPF metadata, navigation, manifest, and ZIP files.

Matched

Can it be fixed automatically?

A checked repair is possible when the generated EPUB has one clear mismatch, such as a path, manifest item, media type, OPF field, navigation declaration, or ZIP issue that can be changed and validated again.

Matched

What to check next

Use the reflowable EPUB exported from InDesign.

Matched

What not to assume

It cannot repair fixed-layout design, change print layout, improve typography, choose reading order from visual pages, restore missing source assets, convert PDFs, or decide KDP review outcomes.

1. Example report output

What an InDesign export report should show.

A useful report should name the generated file before you touch the layout source.

Export checked

The reflowable EPUB exported from InDesign.

Generated content

XHTML, CSS, images, fonts, nav.xhtml, toc.ncx, content.opf, manifest entries, and ZIP entries.

Common blocker

Missing linked asset, stale CSS path, undeclared manifest item, wrong media type, broken generated anchor, or TOC wiring issue.

Decision

Checked repair, re-export from InDesign, manual EPUB review, unsupported, or no supported blocker found.

The report should tell you whether the exported package has one clear mismatch or whether the source/export settings need the fix.

2. Next step

Choose package repair or InDesign export fix.

InDesign EPUB issues are easy to overfix unless you start with the exact generated path.

Trace path

The report names a generated file.

Start with the XHTML, CSS, image, font, OPF, nav, or ZIP path before editing.

Checked repair

The generated target exists and is unique.

Repair may be safe for path case, manifest, media type, OPF, navigation, or ZIP wiring when references stay consistent.

Re-export

The source asset or reading order is wrong.

Return to InDesign when linked images, styles, TOC order, fixed-layout behavior, or missing content must be corrected at source.

3. Concrete path example

An InDesign EPUB can fail because CSS references an image path that was not packaged.

Generated stylesheets can point to files that changed during export or asset cleanup.

Report:
Source file: OEBPS/Styles/idGeneratedStyles.css
Referenced file: ../Images/sidebar-bg.png
ZIP target: missing
Decision: manual review; restore the asset or remove the CSS reference in the source/export workflow

If one same-name image exists under a clear path, the report may suggest repair. If the asset is missing, re-export from InDesign with the right source files.

Quick decision

Decide whether this is an InDesign EPUB structure issue.

Use this for reflowable EPUB package validation. It is not a print-layout or fixed-layout repair tool.

Good fit

You have a reflowable InDesign EPUB.

The scanner can inspect generated XHTML/CSS paths, images, fonts, OPF metadata, navigation, manifest entries, media types, and ZIP packaging.

Manual fit

The path is found but the source decision is unclear.

Use the report to find the generated file, then fix the source layout, linked asset, export setting, or EPUB editor state.

Not this tool

You need fixed-layout, print, or design repair.

Fixed-layout EPUBs, PDF/print layout, typography, image quality, and visual design work are outside this scanner.

Common situations

Common InDesign EPUB export cases.

Start with the generated EPUB file, not the .indd layout.

Matched

Images or CSS fail validation after export.

Generated CSS or XHTML may point to a linked image that was renamed, omitted, or never declared in the manifest.

Scan the EPUB and compare the source path with the packaged target.

Matched

The generated table of contents is disconnected.

InDesign can output nav.xhtml or toc.ncx entries that do not match the OPF manifest, spine, or generated chapter ids.

Check nav, NCX, OPF, and generated ids before rebuilding TOC entries.

Matched

Media types do not match exported files.

A file can keep a .jpg extension while the actual bytes are PNG, or a font can be declared with the wrong media type.

Repair only when the real file type is clear and references can stay consistent.

InDesign export phrases to check

Check EPUB after InDesign export: scan generated XHTML, CSS, images, OPF, nav.xhtml, toc.ncx, links, anchors, manifest, media type, container.xml, and ZIP blockers.

Where InDesign EPUB blockers usually appear

A reflowable EPUB exported from InDesign fails KDP, Kindle Previewer, EPUBCheck, or another validator, often around generated assets, CSS, navigation, OPF, manifest, or media types.

What it means

Generated XHTML, CSS, and images can drift from the OPF package map.

InDesign export blockers often come from missing linked assets, CSS paths to absent files, undeclared manifest items, wrong media types, generated anchors, disconnected nav.xhtml or toc.ncx, OPF identifier issues, and ZIP packaging mistakes.

Before you edit

Check image paths, CSS, manifest entries, and navigation before another export.

Do not patch random XHTML or CSS. First find out whether the blocker is a missing linked asset, wrong media type, stale generated path, disconnected navigation file, or a layout/source problem that belongs back in InDesign.

  1. 1Use the reflowable EPUB exported from InDesign.
  2. 2Keep the InDesign source and linked assets available for re-export.
  3. 3Check whether the report names generated XHTML, CSS, image, font, OPF, nav.xhtml, toc.ncx, manifest, media type, container.xml, or ZIP paths.
  4. 4Use checked repair only for one clear generated-package mismatch that passes EPUBCheck again.
  5. 5Return to InDesign when source assets, layout, TOC order, fixed-layout behavior, or image choices need source-level changes.
  6. 6Do not use this scanner for print PDF, paperback cover, fixed-layout, comic, or image-first EPUB design work.

Why validators check it

Why InDesign EPUB exports need package-level validation.

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.

KDP eBook file formats

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

Repair example

When an InDesign EPUB issue can be repaired here.

Before / after example

Before: content.opf declares a JPEG but the packaged image is actually PNG. After: the manifest media type can be aligned if the image is readable and references remain consistent. Before: an image is missing; restore it in InDesign and export again.

Ready to retry?

Upload the exported InDesign EPUB for a structure scan.

Use the reflowable EPUB output. The report tells you whether the fix is a small package repair, an InDesign export setting, a missing linked asset, or a manual EPUB review item.

Upload EPUB to scan

FAQ

Questions authors ask after InDesign EPUB export.

Can EPUB Fixer check an EPUB exported from InDesign?

Yes, when it is a reflowable .epub. The scan can name generated paths, package fields, and repair decisions for supported validation blockers.

Does this fix InDesign layout or fixed-layout EPUB problems?

No. It does not repair visual layout, typography, print PDF output, or fixed-layout books. It only checks supported EPUB structure issues in reflowable EPUB output.

What if an image is missing from the InDesign EPUB?

If the image is not packaged anywhere, restore the linked asset or export again from InDesign. EPUB Fixer can point to the missing reference, but it should not invent image files.

Can it fix OPF media-type problems from InDesign?

Sometimes. If the file bytes clearly identify the true type and the references can stay consistent, a checked repair may be possible.

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