EPUB error guide
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.
Scan when the message does not name the affected path. The report shows affected paths and repair decisions. Your original EPUB stays unchanged.
Need fixed-layout, DRM, or source-file help? Check unsupported or review-first EPUB cases.
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Start here
An RSC_007 line in an EPUB report often contains two clues: the file being checked and the resource it cannot reach. Keep both before editing the package.
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.
Safe RSC_007 reference fixes are limited to exactly one existing packaged path that differs only by letter case, URL encoding, or both. A separate manifest issue may be repairable under its own evidence. The repaired EPUB must pass EPUBCheck again.
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.
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.
1. Example report output
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 because Text/chapter-03.xhtml differs from the requested path by letter case and is the single equivalent path.
Do not do this
Do not point nav.xhtml to a random nearby chapter just to clear the RSC_007 line.
Automatic repair is limited to one existing path with only case or URL-encoding differences. Moved, renamed, absent, or competing targets remain manual.
2. Next step
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
Group messages by source file first; one folder rename can create many missing-resource lines.
Manual check
Navigation repairs can change what Kindle shows in Go To, so confirm the target chapter before changing the link.
Repair summary
Send the missing target path and the original manuscript/export project so the file can be restored correctly.
3. Concrete path example
This is safe because the existing packaged target differs only by letter case.
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
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.
Scan first
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.
Safe fix
RSC_007 means the link points to a ZIP path that EPUBCheck cannot find. Automatic repair requires exactly one existing path that is equivalent after letter-case or URL-encoding comparison.
Manual/source fix
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.
Common situations
An RSC_007 in a chapter is not the same as an RSC_007 in nav.xhtml, CSS, or content.opf.
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.
Update automatically only when exactly one existing path differs by case or URL encoding. Folder moves or renamed assets require manual confirmation.
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.
Chapter renames and split/merge exports often leave navigation files behind.
Fix automatically only for one case or URL-encoding difference. A changed chapter name or location requires manual reading-order confirmation.
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.
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.
RSC_007: Referenced resource could not be found in the EPUB.
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
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
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.
Why KDP checks it
EPUBCheck checks EPUB 2 and EPUB 3 files against the official rules and reports package, markup, link, and file-reference problems.
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
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?
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.
Upload EPUB to scanFAQ
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.
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.
Sometimes. The reference can be repaired automatically only when one existing packaged path differs by case or URL encoding. A separate confirmed manifest issue can use its own repair rule. Missing, moved, or renamed files require manual restoration or re-export.
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.
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.
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.
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.
