EPUB OCF container
The EPUB container must expose the package document through the expected container structure, including META-INF/container.xml and the packaged resources it points to.
EPUB error guide
container.xml missing in EPUB
Why META-INF/container.xml matters and when a missing EPUB container file can be rebuilt.
Error text
RSC_002: Required META-INF/container.xml resource could not be found.
When you usually see it
The EPUB archive exists, but validators cannot locate the OPF package file that describes the book.
Plain English
What it means inside the EPUB.
container.xml is the pointer that tells EPUB readers where the package document lives.
The file may be missing, placed in the wrong folder, or the EPUB may have been zipped from the wrong directory level.
User checklist
What to inspect before another upload.
These checks keep the repair decision tied to the EPUB package instead of guessing from a generic error code.
- Check whether the EPUB ZIP contains META-INF/container.xml at the correct path.
- Check whether there is exactly one valid OPF package file in the archive.
- Do not rebuild the container automatically when multiple OPF files or multiple renditions are present.
Standards context
Why this error matters to validators.
EPUBCheck
EPUBCheck evaluates EPUB 2 and EPUB 3 publications against official EPUB specifications and reports structure, package, markup, and reference problems.
Repairability
Can EPUB Fixer repair it?
Safe repair condition
EPUB Fixer can rebuild a minimal container.xml when there is exactly one clear OPF file in the package.
When it stops at diagnosis
Automatic repair is unsafe when there are multiple OPF files, multiple renditions, severe ZIP damage, encryption, or no valid package file.
Before / after example
Before: META-INF/container.xml is absent. After: META-INF/container.xml points to the single detected OPF package path.
Next step
Scan the actual file before editing by hand.
The same error code can come from different files and different causes. Uploading the EPUB lets the report show the affected path and whether the fix is deterministic.
Upload EPUB to scan