Match the report title.
Look for "RSC_003 no rootfile tag in container.xml" or the closest title above. Keep the original EPUBCheck, KDP, or Kindle Previewer wording if it differs.
EPUB error guide
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 when the message does not name the affected path. The report shows affected paths and repair decisions, not manuscript text.
Fixed-layout, DRM, or source-workflow issue? Check unsupported or review-first EPUB cases.
Match these report titles
Use this guide when
Your message matches "RSC_003 no rootfile tag in container.xml" or one of the report titles above.
Upload if
You have the exported reflowable .epub and need the affected path, file, field, or repair decision before editing.
Handle outside this tool
Use the source tool or publishing workflow for DOCX, PDF, KPF, KCB, fixed-layout, comics, image-first books, DRM, visual design, or KDP listing and approval problems.
Read the scan report
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.
Look for "RSC_003 no rootfile tag in container.xml" or the closest title above. Keep the original EPUBCheck, KDP, or Kindle Previewer wording if it differs.
Use the Affected area, Source file, Target file, or Problem type rows before editing OPF, nav, XHTML, CSS, or image paths.
Repairable means one clear structural change. Needs review or Not supported means use the named file, source project, or platform step.
Copy these fields from the report instead of rebuilding the fix from memory.
1. Example report output
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
The missing XML tag is easy to add; the important decision is whether the target OPF is unambiguous.
Scan first
Check whether the EPUB contains zero, one, or multiple .opf files before editing container.xml.
Safe repair
Add rootfile only when one OPF has the metadata, manifest, and spine for this book.
Manual review
Stop when there are multiple OPF files, nested exports, or multiple renditions.
3. Concrete path example
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
A rootfile entry controls which package document the reading system opens.
Scan first
Record whether container.xml exists and list every .opf file in the EPUB.
Safe fix
Add a rootfile entry pointing to that OPF path exactly, then run validation again.
Stop
Do not choose between multiple OPF files or nested package folders automatically.
Start here
RSC_003 means the container map exists, but it does not name the OPF package file. Do not patch random OPF files until the real package file is clear.
The EPUB has a container map, but the map does not tell readers which OPF package file to open.
It can be repaired when the EPUB contains one clear OPF package file and only the rootfile pointer is missing.
Open META-INF/container.xml and check whether a rootfile entry exists.
It is unsafe when the OPF file is missing, there are multiple OPF files, or the package layout needs a publishing decision.
Common situations
Most RSC_003 errors come from manual EPUB edits or broken export packaging.
The file exists under META-INF, but it has no rootfiles block.
Add a rootfile only after confirming the real OPF path.
The package files are present, but the container map was damaged.
Rebuild the container map from the package layout.
Old exports or multiple renditions can leave competing package files.
Choose manually instead of guessing.
container.xml cannot point to a package file that is not present.
Return to the source export or restore the package file.
RSC_003: No rootfile tag was found in the container.
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, but the map does not tell readers which OPF package file to open.
This often happens after manual zipping, broken EPUB editing, or export cleanup that leaves container.xml incomplete.
Before you edit
A safe fix depends on finding one real OPF package file and adding a rootfile entry that points to it exactly.
Why KDP checks it
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.
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 checks EPUB 2 and EPUB 3 files against the official rules and reports package, markup, link, and file-reference problems.
Can this be fixed safely?
It can be repaired when the EPUB contains one clear OPF package file and only the rootfile pointer is missing.
It is unsafe when the OPF file is missing, there are multiple OPF files, or the package layout needs a publishing decision.
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?
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
It means META-INF/container.xml exists, but EPUBCheck cannot find a rootfile entry that points to the OPF package file.
It can help when there is one clear OPF package file and container.xml only needs the missing rootfile entry restored.
No. RSC_002 means container.xml is missing. RSC_003 means the file exists but does not contain the package pointer EPUB readers need.
No. First find whether a valid OPF file already exists. Creating a package file is not a safe automatic repair.