Checked repair
Download can appear
Only when EPUB Fixer writes a deterministic structure repair and the repaired EPUB passes the second EPUBCheck run.
Preview a sample EPUB scan report
This is the same report layout you see after upload. Use it to check whether the output is useful before you scan your own EPUB.
Three sample reports below show the three possible outcomes: a checked repair with a download, a report that stops for manual review, and a file that is unsupported by this scanner.
Possible results
Know the boundary before you upload.
Needs review
No checked download yet
Use the affected path, original error, and copy summary for the person editing the EPUB.
Unsupported here
Stop and fix the source workflow
Return to the source export, fixed-layout, conversion, DRM, or editor workflow before scanning again.
Sample 1 of 3
Checked repair — download is available
This sample shows what the report looks like when the repaired file passes the second EPUBCheck run. The download section and retry form appear only in this state.
Scan report
Checked repair available
A checked EPUB download is ready.
The repaired file passed a second EPUBCheck run here, so this copy is ready to test at the platform where your original upload failed.
Download this checked EPUB, then retry the same file.
Use KDP, Kindle Previewer, or EPUBCheck again before treating this copy as final.
Report snapshot
- Issues found
- 3 issues found
- Download
- Repaired file ready
- Repairable
- 3
- Checked changes
- OPF package identifier, OPF manifest media type, EPUB 3 modified timestamp
| Scan status | Scan complete |
|---|---|
| File type | Reflowable EPUB |
| Download | Repaired file ready |
| Checked repair changed | OPF package identifier, OPF manifest media type, EPUB 3 modified timestamp |
| Repair summary | 3 auto-fixes were applied and the repaired file is ready for retry. |
| Initial EPUBCheck evidence | EPUBCheck 5.3.0 · EPUB 3.0 · 0 fatal · 2 errors · 1 warnings |
| Second EPUBCheck evidence | EPUBCheck 5.3.0 · EPUB 3.0 · 0 fatal · 0 errors · 0 warnings |
| Post-repair result | The repaired EPUB passed the second EPUBCheck run and the post-repair structure scan, so the checked download is available. |
| Retry evidence | EPUBCheck passed, KDP still failed, Kindle Previewer not tried yet, same error |
| Error you reported before upload | OPF-048: package unique-identifier is missing in OEBPS/content.opf |
| Report ID | sample-checked-repair |
Checked in this report
- OPF metadata and package wiring
- Manifest entries and media types
- Internal links and resource paths
Your platform error
1 scan finding uses the same error code and EPUB path as the error you saved.
Open the matched finding below to compare the affected EPUB path and next step. This match does not predict whether KDP or another platform will accept the file.
Recommended order
Use the repaired EPUB for one retry, then save the result.
Use the download below, retry the same file where it failed, then mark the result on this report.
- Step 1Download this fileUse the repaired EPUB from this report, not another export.
- Step 2Retry it where it failedTry KDP, Kindle Previewer, or EPUBCheck before treating it as final.
- Step 3Save what happenedMark passed, still failed, or not tried yet on this report.
Status
Checked repair available
- File to retry
- Repaired EPUB package
- Next owner
- Author
- EPUB Fixer result
- Already repaired and checked here.
- What to record next
- Latest retry evidence: EPUBCheck passed, KDP still failed, Kindle Previewer not tried yet, same error.
Before and after
The follow-up checks found no remaining issues.
This compares the first scan with the second EPUBCheck run and the post-repair structure scan. “No longer found” is limited to those checks and is not a promise of platform acceptance.
- First scan
- 3
- No longer found
- 3
- Still found
- 0
- New in follow-up
- 0
- Files changed
- 2
Changed files: OEBPS/content.opf · OEBPS/images/cover.png
Why this download can be retried
Only changes that passed the second check are listed here.
Use this if you need to confirm what changed before retrying the repaired EPUB.
Changed
OEBPS/content.opf- Repair type
- OPF package identifier
- Before
- package unique-identifier was missing
- After
- package unique-identifier="bookid"
- Why this change was clear
- The OPF already had one clear identifier to reuse.
- Second EPUBCheck
- The repaired EPUB reopened with the intended files and contents unchanged after repacking. Second EPUBCheck passed.
Changed
OEBPS/images/cover.png- Repair type
- OPF manifest media type
- Before
- media-type="image/jpeg"
- After
- media-type="image/png"
- Why this change was clear
- The existing file extension matched one deterministic image type.
- Second EPUBCheck
- The repaired EPUB reopened with the intended files and contents unchanged after repacking. Second EPUBCheck passed.
Changed
OEBPS/content.opf- Repair type
- EPUB 3 modified timestamp
- Before
- dcterms:modified was missing
- After
- dcterms:modified set to 2026-05-04T08:15:00Z
- Why this change was clear
- EPUB 3 requires one UTC modified timestamp, so EPUB Fixer used the repair time.
- Second EPUBCheck
- The repaired EPUB reopened with the intended files and contents unchanged after repacking. Second EPUBCheck passed.
Issue list
Package and manifest issues (3)
3 issues already have a checked repair. Download the repaired EPUB and retry that file.
The package or manifest wiring in this group was already changed and then checked again with EPUBCheck before the repaired download was shown.
Next: Try it in KDP, Kindle Previewer, or EPUBCheck, then save whether it passed or still failed.
Affected file: OEBPS/content.opf
- Check first
- OPF package identifier in OEBPS/content.opf
- Issue
- The OPF package does not tell EPUBCheck which dc:identifier is the book's main identifier.
- Why this can be repaired
- Can auto-fix only when the OPF has one clear dc:identifier to use as the book identifier.
- Next step
- Open content.opf, find the package tag, and point unique-identifier only to one existing dc:identifier id that is clearly the book identifier. If ISBN, UUID, retailer, or draft ids compete, choose manually before editing.
- Original error
- OPF_048 Package unique-identifier is missing
Opens the paragraph for adding the package unique-identifier pointer. Use it with the affected OPF file shown in this report.
Open repair guideAffected file: OEBPS/images/cover.png
- Check first
- OPF manifest media type for OEBPS/images/cover.png
- Issue
- The OPF manifest says this file has one media type, but the file extension or content points to another type.
- Why this can be repaired
- Can auto-fix when the same packaged file is clearly correct and only the OPF media type is wrong; if the asset itself may be wrong, it still needs source review.
- Next step
- Check the manifest href, keep the same packaged file only when it is the intended asset, and change media-type to the real file type without renaming or swapping the file blindly.
- Original error
- OPF_029 Manifest media-type does not match the file extension
Opens the paragraph for this media-type mismatch and highlights the content.opf change to check.
Open repair guideAffected file: OEBPS/content.opf
- Check first
- OPF modified timestamp in OEBPS/content.opf
- Issue
- The EPUB 3 modified timestamp is missing or appears more than once.
- Why this can be repaired
- Can auto-fix when EPUB Fixer only needs to leave one clear UTC dcterms:modified entry in the OPF metadata.
- Next step
- Keep exactly one meta property="dcterms:modified" entry in UTC format. If the OPF metadata block is duplicated or inconsistent, review the whole metadata section before retrying.
- Original error
- EPUB 3 dcterms:modified metadata is missing
Opens the paragraph for the OPF modified timestamp and highlights the metadata change to check.
Open repair guideSample 2 of 3
Needs manual review — no checked download yet
This sample shows what the report looks like when issues require a decision before any automatic repair can run. The affected path and next step are visible, but no download appears.
Scan report
Review needed before retry
A checked download is not ready for this EPUB.
Resolve the remaining issues before you expect a repaired download.
Review the remaining issues before you retry this EPUB.
Start with Link and anchor issues: Affected file: OEBPS/nav.xhtml. Use the decision flow below to keep the paths, errors, and next step together while you fix the source file.
Review manual issuesReport snapshot
- Issues found
- 2 issues found
- Download
- Not available
- Needs review
- 2
| Scan status | Scan complete |
|---|---|
| File type | Reflowable EPUB |
| Download | Not available |
| Repair result | No checked repair was created |
| Repair summary | 2 manual-review issues need attention before retrying KDP. |
| Error you reported before upload | RSC-012: OEBPS/nav.xhtml points to a missing fragment in OEBPS/Text/chapter-02.xhtml#intro-section |
| Report ID | sample-needs-review |
Checked in this report
- Navigation, NCX, and spine wiring
- Internal links and resource paths
- XHTML structure
- OPF metadata and package wiring
Your platform error
1 scan finding uses the same error code and EPUB path as the error you saved.
Open the matched finding below to compare the affected EPUB path and next step. This match does not predict whether KDP or another platform will accept the file.
Recommended order
Start with the issue that still needs a decision.
Use the open issue as the handoff: affected file, original error, and the exact thing someone must confirm before editing.
- Step 1Open the blockerUse the highlighted issue group as the first checklist.
- Step 2Prepare the handoff summaryKeep the path, validator message, and next check together for the person editing the EPUB.
- Step 3Use the report detailsUse the report details before changing the source file.
Guided repair
Start with: RSC_012 fragment identifier is not defined
The report can order the checks, but it cannot choose the intended book content for you. Work on this one blocker, then export a new EPUB and scan that new file.
Open the affected EPUB area
Open OEBPS/nav.xhtml in the source EPUB or EPUB editor.
Confirm what should change
Use the source EPUB or editor to confirm which file, link, identifier, or reading order is intended. Continue only when one choice is clear.
Make the smallest confirmed edit
Split the link at #, confirm the target file exists, then compare the fragment with real ids in that file. Only retarget the link when one existing anchor is clearly the same reading location.
Build a new EPUB and check it again
Save or export a new EPUB, run EPUBCheck, then scan that new file here. Do not treat this report as proof that the edited file passes.
Stop here if: the correct change is not clear from the source EPUB or more than one edit could be valid.
Scan result
Manual anchor decision
- Affected file
- OEBPS/nav.xhtml
- Who should handle it
- EPUB editor
- Can EPUB Fixer handle it here?
- No, confirm the intended target before editing or uploading again.
- What to check next
- You need to confirm the intended target before editing.
Scan result
Manual navigation decision
- Affected file
- OEBPS/toc.ncx
- Who should handle it
- Author or EPUB editor
- Can EPUB Fixer handle it here?
- No, confirm the intended target before editing or uploading again.
- What to check next
- You need to confirm the intended target before editing.
Issue list
Link and anchor issues (1)
You or a formatter need to confirm the intended target for 1 issue before another upload.
EPUB Fixer only auto-fixes this group when one file path or one anchor target is the clear match.
Next: Use the issue details below to confirm the intended file path or reading anchor before you change the EPUB or export again.
Affected file: OEBPS/nav.xhtml
- Check first
- Broken internal link anchor in OEBPS/nav.xhtml
- Issue
- A link points to an anchor id that does not exist in the target XHTML file.
- Why this needs review
- Needs manual review when the missing fragment belongs to a footnote, backlink, repeated heading, or any link where the reader destination is not obvious.
- Next step
- Split the link at #, confirm the target file exists, then compare the fragment with real ids in that file. Only retarget the link when one existing anchor is clearly the same reading location.
- Original error
- RSC-012: file 'OEBPS/Text/chapter-02.xhtml' referenced in 'OEBPS/nav.xhtml' with fragment identifier '#intro-section' could not be found
Opens the paragraph for this missing anchor and highlights what to check before editing the link.
Open repair guideTOC and navigation issues (1)
You or a formatter need to confirm the intended target for 1 issue before another upload.
EPUB Fixer only auto-fixes deterministic EPUB 2 NCX or spine wiring in this group. It does not choose or mark an EPUB 3 navigation file for you.
Next: Use the issue details below to confirm the intended nav file, NCX file, spine order, or TOC target before you change the EPUB or export again.
Affected file: OEBPS/toc.ncx
- Check first
- EPUB file path: OEBPS/toc.ncx
- Issue
- The EPUB navigation, NCX, or spine wiring needs review.
- Why this needs review
- Open the NCX and OPF spine wiring before changing the EPUB.
- Next step
- Use the affected path and original error to decide whether the file, OPF entry, or link target should change.
- Original error
- NCX-001: The NCX identifier does not match the package unique-identifier.
Use this guide to check navigation files and spine/NCX wiring before rebuilding the table of contents.
Open repair guideSample 3 of 3
Unsupported by this scanner — stop and fix the source
This sample shows what the report looks like when the EPUB is outside the current repair scope. The report explains why the scan stopped and what to fix before uploading again.
Scan report
Needs source export fix
This file is not supported by this scanner.
The scan stopped at fixed layout. Try a text-first EPUB 2 or EPUB 3 file without fixed-layout pages, DRM, image-first content, or source/conversion files.
Use a supported EPUB export before scanning again.
The scan stopped at fixed layout. Try a text-first EPUB 2 or EPUB 3 file without fixed-layout pages, DRM, image-first content, or source/conversion files.
Check unsupported filesReport snapshot
- Issues found
- 1 issue found
- Download
- Not available
- Unsupported
- 1
| Scan status | Not supported |
|---|---|
| File type | fixed layout |
| Download | Not available |
| Repair result | No checked repair was created |
| Repair summary | No checked repair was created because this file is outside EPUB Fixer's deterministic repair rules. Export a supported reflowable EPUB before scanning again. |
| Report ID | sample-unsupported |
Checked in this report
- OPF metadata and package wiring
- Unsupported scope checks
Recommended order
Fix the source export before scanning again.
This upload stopped before EPUB structure repair. Fix the source export and scan the EPUB again.
- Step 1Read the stop reasonConfirm why this file did not reach a checked repair.
- Step 2Fix the source exportUse the source tool or EPUB package step named in the report.
- Step 3Upload againScan the corrected EPUB when the package is ready.
Stop reason
Unsupported preflight stop
- Affected file
- fixed-layout.epub
- Who should handle it
- Source export or EPUB editor
- Can EPUB Fixer continue here?
- No, this is outside EPUB Fixer's deterministic repair rules.
- What to do next
- The scan stopped at fixed layout. Try a text-first EPUB 2 or EPUB 3 file without fixed-layout pages, DRM, image-first content, or source/conversion files.
Issue list
Package and manifest issues (1)
1 issue is outside EPUB Fixer's deterministic repair rules.
Use the issue details below to confirm the intended OPF, manifest, or package target in your source export or EPUB editor.
Next: Leave this report and use your source export or EPUB editor to correct the OPF or package file manually before scanning another EPUB.
Affected file: OEBPS/content.opf
- Check first
- EPUB layout metadata in OEBPS/content.opf
- Issue
- This is a fixed-layout EPUB. EPUB Fixer handles reflowable EPUB structure issues, not fixed-layout page repair.
- Why this stops here
- Not supported here because changing fixed-layout files requires layout judgment.
- Next step
- Export a reflowable EPUB if that is possible, or fix the fixed-layout file in the source tool or EPUB editor.
- Original error
- Fixed-layout EPUB metadata detected
This report found a fixed-layout EPUB, so the guide opens the matching unsupported item.
Open fixed-layout guideUse your file
Ready to check your EPUB?
Upload the EPUB before KDP upload or after KDP, Kindle Previewer, or EPUBCheck fails to see the affected paths, repair decisions, and next steps for your own file.