Use this when you already have the exact RSC_007 line. Follow the source file and missing target path before you change nav.xhtml, content.opf, chapters, images, or CSS.
RSC_007: Referenced resource could not be found in the EPUB.
Read the scan report
How to decide whether this report item matches RSC_007 referenced resource could not be found.
Use the report label, affected file, and repair decision together. A matching title alone is not enough if the file path or EPUB structure points to a different problem.
Match the report title.
Look for "RSC_007: Referenced resource could not be found in the EPUB." or the closest title listed above. If the platform wording is different, keep the original EPUBCheck, KDP, or Kindle Previewer message before choosing a fix.
Check the affected file first.
Use the report's Affected area, Source file, Target file, or Problem type rows before editing content.opf, nav.xhtml, toc.ncx, XHTML, CSS, or image paths.
Follow the repair decision.
Repairable means EPUB Fixer found one clear structural change. Needs review or Not supported means use the named file, source project, or platform step instead of guessing.
Repair summary
What to keep if this is not safely repairable.
Copy the report summary instead of rebuilding the fix from memory. A useful repair note keeps the source file, target file or field, original error, repair decision, and next step together.
Source file
Target path or field
Original error
Repair decision
Next step
1. Example report output
What an RSC_007 report should make clear.
The report should connect the exact validator text to the source file, missing target, and repair decision.
EPUBCheck message
ERROR(RSC-007): OEBPS/nav.xhtml(12,45): Referenced resource "text/chapter-03.xhtml" could not be found in the EPUB.
KDP / Previewer wording
The EPUB contains a missing or broken internal file reference.
EPUB Fixer report
Source path OEBPS/nav.xhtml, broken target text/chapter-03.xhtml, closest match Text/chapter-03.xhtml.
Do this next
Repair only if Text/chapter-03.xhtml is the single matching chapter file, then validate again.
Do not do this
Do not point nav.xhtml to a random nearby chapter just to clear the RSC_007 line.
If several chapter files could match, stop and confirm the intended reading order before editing nav.xhtml.
2. Next step
Choose the next step from the source and target.
RSC_007 is common, but the fix depends on whether the missing target is an image, CSS file, chapter, nav file, NCX entry, or OPF reference.
Upload scan
Use this when there are multiple RSC_007 messages.
Group messages by source file first; one folder rename can create many missing-resource lines.
Manual check
Use this when a nav or NCX file is involved.
Navigation repairs can change what Kindle shows in Go To, so confirm the target chapter before changing the link.
Repair summary
Use this when source assets are absent.
Send the missing target path and the original manuscript/export project so the file can be restored correctly.
3. Concrete path example
A typical RSC_007 path mismatch.
This is the kind of case that can be safe when there is only one packaged target.
Matched
Message: ERROR(RSC-007): OEBPS/nav.xhtml references text/chapter-03.xhtml
Report shows: OEBPS/nav.xhtml -> text/chapter-03.xhtml
Found: Text/chapter-03.xhtml
Fix: update nav.xhtml only if this is the intended chapter
Do not apply this pattern when two chapter files could be valid targets.
Quick decision
Do not fix RSC_007 from the code alone.
The code tells you the category. The source file and target path tell you whether this is a safe path repair, a manifest problem, or a missing source asset.
Matched
Scan first
You have more than one RSC_007 line.
Scan the EPUB and group the errors by source file. One moved folder can create many messages, and fixing the root path is safer than editing each link blindly.
Matched
Safe fix
One source points to one obvious packaged target.
RSC_007 means the link points to a ZIP path that EPUBCheck cannot find. Case-only, percent-encoding, and simple relative-path mistakes can be repaired when the report shows one matching packaged file and no competing target.
Matched
Manual/source fix
The target is absent or several matches exist.
If the target file is not in the EPUB, restore it from the source project or re-export. If several files look similar, do not guess; choosing the wrong image, chapter, or stylesheet can make the EPUB validate while showing the wrong content.
Start here
Use the RSC_007 path before touching the EPUB.
An RSC_007 line often contains two clues: the file being checked and the resource it cannot reach. Keep both. The repair decision depends on that pair, not just on the error code.
Matched
What it means
RSC_007 means one file inside the EPUB points to another packaged file that cannot be resolved at that exact path. The book may still display in Calibre because some readers skip the missing image, stylesheet, chapter, nav, or NCX target instead of rejecting the package.
Matched
Can it be fixed automatically?
Safe fixes include obvious path case differences, URL encoding mismatches, relative path mistakes, or missing manifest declarations when the package contains one clear target. After the change, the EPUB should pass EPUBCheck again so a different RSC_007 line is not hiding behind the first one.
Matched
What to check next
Start with the file path in the error message and find the file that contains the broken link, image source, CSS url(), nav entry, NCX entry, or manifest reference.
Matched
What not to assume
The repair is not safe to automate when several files could match, when the referenced resource is absent from the EPUB, or when replacing it would require deciding what the book should contain. In those cases the correct fix is usually to restore the original image, CSS, XHTML, nav, or NCX file from the source project and export the book again.
Common situations
Use the source file to understand the RSC_007 case.
An RSC_007 in a chapter is not the same as an RSC_007 in nav.xhtml, CSS, or content.opf.
Matched
XHTML image or link path is broken.
A chapter can point to ../Images/Cover.jpg while the EPUB contains images/cover.jpg. EPUB paths are case-sensitive, so a file that opens locally can still fail validation.
Compare the path from the chapter file's folder, then update the reference only when one packaged image or chapter is the clear target.
Matched
CSS references a missing font or background image.
CSS url(...) paths are resolved from the stylesheet's folder, not from the chapter. A moved stylesheet can make fonts or background images look missing.
Confirm the asset exists at the resolved ZIP path and is declared in the OPF manifest before changing the CSS URL.
Matched
nav.xhtml or toc.ncx points to an old chapter name.
Chapter renames and split/merge exports often leave navigation files behind.
Fix the nav or NCX target only when the intended chapter is unambiguous; otherwise check the reading order manually.
Matched
The file is present but not wired through the package.
Sometimes the target exists in the ZIP, but the package inventory or relative reference still makes validators treat it as unreachable.
Align the OPF manifest or the reference path, then run EPUBCheck again before making another edit.
Matched
The OPF manifest still names a removed file.
A deleted image, stylesheet, or XHTML file can remain in content.opf even after the export tool removed it from the package.
Remove or correct the manifest item only after confirming the file is not used by a chapter, nav file, NCX file, or stylesheet.
The RSC_007 error text
RSC_007: Referenced resource could not be found in the EPUB.
Where RSC_007 shows up during EPUB validation
KDP, Kindle Previewer, or EPUBCheck reports RSC_007 during validation, often after an export, file rename, manual ZIP edit, image optimization pass, or a retry on a file that still opens in a local reader.
What it means
RSC_007 starts when one internal reference cannot resolve.
RSC_007 means one file inside the EPUB points to another packaged file that cannot be resolved at that exact path. The book may still display in Calibre because some readers skip the missing image, stylesheet, chapter, nav, or NCX target instead of rejecting the package.
The broken pointer can live in XHTML href or src attributes, CSS url() values, OPF manifest references, nav links, NCX content sources, image references, or stylesheet imports. Common causes are letter-case changes, renamed folders, spaces or URL encoding differences, files moved during export, and files present in the ZIP but not wired the way the package expects.
Before you edit
Trace the source file to the missing target path.
Work one reported path at a time. Fixing a case mismatch is different from restoring a missing image, and both are different from an OPF manifest issue.
1Start with the file path in the error message and find the file that contains the broken link, image source, CSS url(), nav entry, NCX entry, or manifest reference.
2Record the missing target separately from the source file. The source tells you where to edit; the target tells you what the package failed to resolve.
3Compare the referenced path with the real file path inside the EPUB, including folder, letter case, spaces, URL encoding, and ../ relative path segments.
4If the target file exists, check whether content.opf declares it when it is an image, CSS file, XHTML file, font, nav file, or NCX file used by the book.
5If there is one obvious match, such as Cover.jpg versus cover.jpg, fix the path and validate again before making a second change.
6If several files could be the intended target, or the file is not packaged at all, restore the source file or review manually instead of guessing.
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.
Can this be fixed safely?
When an RSC_007 repair is safe enough to automate.
When automatic repair is safe
Safe fixes include obvious path case differences, URL encoding mismatches, relative path mistakes, or missing manifest declarations when the package contains one clear target. After the change, the EPUB should pass EPUBCheck again so a different RSC_007 line is not hiding behind the first one.
When you need manual review
The repair is not safe to automate when several files could match, when the referenced resource is absent from the EPUB, or when replacing it would require deciding what the book should contain. In those cases the correct fix is usually to restore the original image, CSS, XHTML, nav, or NCX file from the source project and export the book again.
Before / after example
Before: a nav entry points to text/chapter-03.xhtml, but the package contains Text/chapter-03.xhtml. After: the nav link uses the packaged path. Before: chapter1.xhtml references images/diagram.png and the EPUB has no diagram image; that should be restored from the manuscript source, not fabricated.
Ready to retry?
Scan the file before making a second KDP attempt.
A scan can separate a simple path mismatch from a genuinely missing resource, then show whether the same EPUB has more than one broken reference.
RSC_007 means an internal EPUB reference points to a file that EPUBCheck cannot resolve. It often appears in links, image sources, CSS URLs, OPF manifest items, nav files, or NCX entries.
How do I find the broken file behind an RSC-007 error?
Use the path in the EPUBCheck or KDP message as the starting point, then inspect the packaged EPUB files for the closest real match. Compare folder names, capitalization, spaces, URL-encoded characters, and whether the target is declared in the OPF manifest.
Can I fix RSC-007 without re-exporting the EPUB?
Sometimes. If the EPUB package already contains the intended file, a targeted path or manifest correction may be enough. If the file is missing, re-exporting or restoring the original source file is usually required.
Why does my EPUB open in Calibre but fail KDP with RSC-007?
Calibre and other local readers may skip or tolerate a broken image, CSS, nav, or chapter reference. KDP, Kindle Previewer, and EPUBCheck validate the package paths more strictly before accepting the file.
Will Kindle Previewer show the same RSC-007 problem?
Kindle Previewer can report the same underlying broken reference, but the wording may differ from EPUBCheck. The important detail is the affected path and whether the referenced file exists in the EPUB.
What is the difference between RSC-007 and RSC-012?
RSC_007 usually means the referenced file path cannot be found. RSC_012 means the file exists, but the anchor after the # symbol is missing inside that file. The first check is the packaged file path; the second check is the target id inside the XHTML.
Should I fix every RSC_007 line the same way?
No. A broken image path, a missing CSS import, a nav link to a moved chapter, and an undeclared OPF resource can all surface as RSC_007. The affected source file and target path decide the fix.