What it means
The EPUB has a container map, but the map does not tell readers which OPF package file to open.
EPUB error guide
RSC_003 no rootfile tag in container.xml
Use this when EPUBCheck says container.xml has no rootfile tag. Check the EPUB package map before you edit chapters, metadata, or KDP settings.
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
- RSC_003 no rootfile tag in container.xml
- No rootfile tag found in the EPUB container
- container.xml missing rootfile entry
- EPUB package map has no OPF pointer
Start here
Start with container.xml before opening content.opf.
In an EPUB package, RSC_003 means the container map exists, but it does not name the OPF package file.
Can it be fixed automatically?
It can be repaired when the EPUB contains one clear OPF package file and only the rootfile pointer is missing.
What to check next
Open META-INF/container.xml and check whether a rootfile entry exists.
What not to assume
It is unsafe when the OPF file is missing, there are multiple OPF files, or the package layout needs a publishing decision.
1. Example report output
What an RSC_003 report should show.
The report should connect the missing rootfile entry to the OPF file that can actually represent the book.
EPUBCheck message
ERROR(RSC-003): META-INF/container.xml: No rootfile tag was found in the container.
Affected file
META-INF/container.xml.
EPUB Fixer report
container.xml exists, but it has no rootfile full-path value. The EPUB contains OEBPS/content.opf.
Do this next
Add a rootfile entry only if OEBPS/content.opf is the single valid package file.
Do not do this
Do not point rootfile at a random .opf when multiple OPF files exist.
Safe repair means adding a missing rootfile pointer to one clear OPF package file, then validating the EPUB again.
2. Next step
Decide whether one OPF file can be trusted.
The missing XML tag is easy to add; the important decision is whether the target OPF is unambiguous.
Scan first
List every OPF file.
Check whether the EPUB contains zero, one, or multiple .opf files before editing container.xml.
Safe repair
One package file is clear.
Add rootfile only when one OPF has the metadata, manifest, and spine for this book.
Manual review
The package choice is unclear.
Stop when there are multiple OPF files, nested exports, or multiple renditions.
3. Concrete path example
A typical missing rootfile entry.
container.xml exists, but it does not tell readers where the package lives.
EPUBCheck: ERROR(RSC-003): META-INF/container.xml: No rootfile tag was found in the container. Report: container.xml: present Rootfile full-path: missing Found OPF files: OEBPS/content.opf Fix decision: safe only if OEBPS/content.opf is the single package file After: add rootfile full-path, then validate again
If the scan finds several OPF files, choose the package manually before editing container.xml.
Quick decision
Do not add a rootfile until the OPF target is clear.
A rootfile entry controls which package document the reading system opens.
Scan first
Find container.xml and OPF candidates.
Record whether container.xml exists and list every .opf file in the EPUB.
Safe fix
One package file represents the book.
Add a rootfile entry pointing to that OPF path exactly, then run validation again.
Stop
The package map is ambiguous.
Do not choose between multiple OPF files or nested package folders automatically.
Common situations
Common RSC_003 cases.
Most RSC_003 errors come from manual EPUB edits or broken export packaging.
container.xml was created empty.
The file exists under META-INF, but it has no rootfiles block.
Add a rootfile only after confirming the real OPF path.
A manual ZIP rebuild dropped XML content.
The package files are present, but the container map was damaged.
Rebuild the container map from the package layout.
The EPUB contains several OPF files.
Old exports or multiple renditions can leave competing package files.
Choose manually instead of guessing.
The OPF file is missing too.
container.xml cannot point to a package file that is not present.
Return to the source export or restore the package file.
The RSC_003 container.xml error text
RSC_003: No rootfile tag was found in the container.
Where no-rootfile container errors appear
EPUBCheck can read META-INF/container.xml, but the file does not contain a rootfile entry for the OPF package.
What it means
The EPUB has a container map that does not point to the package.
This often happens after manual zipping, broken EPUB editing, or export cleanup that leaves container.xml incomplete.
Before you edit
Compare container.xml with the OPF files inside the EPUB.
A safe fix depends on finding one real OPF package file and adding a rootfile entry that points to it exactly.
- 1Open META-INF/container.xml and check whether a rootfile entry exists.
- 2List every .opf file in the EPUB package.
- 3Confirm whether one OPF file has the book metadata, manifest, and spine.
- 4Check for nested parent folders that may hide the real package root.
- 5Stop if there are zero or multiple plausible OPF package files.
Why KDP checks it
Why validators require a rootfile entry.
EPUB ZIP container
The EPUB ZIP wrapper must point readers to the OPF file through META-INF/container.xml and keep packaged resources at the paths the book references.
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.
EPUBCheck
EPUBCheck checks EPUB 2 and EPUB 3 files against the official rules and reports package, markup, link, and file-reference problems.
Repair example
When RSC_003 can be repaired safely.
Before / after example
Before: container.xml exists without a rootfile entry. After: it points to the one valid OPF package file and EPUBCheck passes the container check.
Ready to retry?
Scan the container map before rebuilding the package.
Upload the EPUB that produced RSC_003. The report should show whether container.xml is missing only the rootfile entry or whether the whole package layout is damaged.
Upload EPUB to scanFAQ
Questions authors ask about RSC_003.
What does RSC_003 mean in EPUBCheck?
It means META-INF/container.xml exists, but EPUBCheck cannot find a rootfile entry that points to the OPF package file.
Can EPUB Fixer repair RSC_003?
A checked repair is possible when there is one clear OPF package file and container.xml only needs the missing rootfile entry restored.
Is RSC_003 the same as container.xml missing?
No. RSC_002 means container.xml is missing. RSC_003 means the file exists but does not contain the package pointer EPUB readers need.
Should I create a new OPF file for RSC_003?
No. First find whether a valid OPF file already exists. Creating a package file is not a safe automatic repair.
Related EPUB error guides
- OPF_030: EPUB unique identifier was not found
- EPUB metadata checker
- dcterms:modified missing in EPUB
- More than one title in OPF metadata (E20006)
- OPF_029: EPUB media type does not match the file
- PKG_021 corrupted image file encountered
- PKG_022 wrong file extension for image
- OPF_003 or RSC_008 item is not declared in the OPF manifest
- OPF_048 package is missing unique-identifier
- OPF_049 item id was not found in the manifest
- EPUB cover-image property is missing
- PKG_007 mimetype file contents invalid or compressed
- OPF_002 OPF file not found in the EPUB
- RSC_002 container.xml missing in EPUB
- OPF_019 spine tag was not found
- EPUB mimetype file missing or not first (PKG-006)