Cannot upload curated JSONCAS/XMI due to missing CASMetadata and CasDoctor errors

[lfcc1]

Describe the bug
Re-uploading a curated CAS (JSONCAS or XMI) via the REST API or pycaprio fails. CasDoctor rejects the CAS due to missing CASMetadata and span validation errors. Normal single-annotator CAS uploads work fine; the issue occurs only with curated CAS.

To Reproduce
Steps to reproduce the behavior:

1 - Export the curated CAS via REST or UI in jsoncas or xmi format.
2- Attempt to re-upload the curated CAS using pycaprio:

curated_bytes = client.api.curation(project_id, doc_id, curation_format="jsoncas")

client.api.create_curation(
    project_id,
    doc_id,
    curation_format="jsoncas",
    content=("curation.json", BytesIO(curated_bytes))
)

Expected behavior
The curated CAS should be uploadable without errors.

Error message
When ulpoading json cas:

"Internal server error: CasDoctor found 3 issues:\nCAS contains no CASMetadata. Cannot check concurrent access.\nType [de.tudarmstadt.ukp.dkpro.core.api.metadata.type.DocumentMetaData] has [1] unreachable instances\n[custom.Span] [Lactifreir\u2026ipessoal ]@[12933-12982] ends with whitespace\n"

When uploading xmi:

"Internal server error: CasDoctor found 2 issues:\nCAS contains no CASMetadata. Cannot check concurrent access.\n[custom.Span] [Alandroal\". ]@[10940-10952] ends with whitespace\n"

Please complete the following information:

• Version: 39.4 (2026-01-20 13:55:09, build 99066443)
• OS: Linux

Additional Context:
I tried the API directly on the Swagger documentation, and got the same errors

[reckart]

You can work around the issue by disabling import checks in your settings.properties:

document-import.run-cas-doctor-on-import=OFF

[reckart]

Mind that annotations ending in whitespace can be a problem. I'd recommend running CAS doctor and checking relevant repairs after import.

[lfcc1]

Hi,

I tried running CAS Doctor before exporting, and also on the project where I’m importing, but the error still persists.

However, after disabling run-cas-doctor-on-import, the import completes successfully.

[reckart]

Did you just run the CAS Doctor checks or did you also run the respective repairs?

[lfcc1]

I ran the repairs (checked all boxes)

[reckart]

Hm. And could you re-run the CAS doctor checks again after the repairs and check whether it still complains about whitespace in annotations. If that were the case, maybe the trim repair has a bug.