HumanSignal/label-studio · error · ValidationError

_old_vs_new_data_keys_inconsistency_message(new_data_fields,

Error message

_old_vs_new_data_keys_inconsistency_message(new_data_fields, common_data_fields, file_upload.file.name)

What it means

During load_tasks_from_uploaded_files, when multiple files are imported/reimported, each file's task data keys must overlap with the keys of previously processed files. If a file's new_data_fields shares no key with common_data_fields, Label Studio raises a ValidationError built by _old_vs_new_data_keys_inconsistency_message naming the offending file.

Source

Thrown at label_studio/data_import/models.py:343

        common_data_fields = set()

        # scan all files
        file_uploads = FileUpload.objects.filter(project=project)
        if file_upload_ids:
            file_uploads = file_uploads.filter(id__in=file_upload_ids)
        for file_upload in file_uploads:
            file_format = file_upload.format
            if formats and file_format not in formats:
                continue
            new_tasks = file_upload.read_tasks(files_as_tasks_list)
            for task in new_tasks:
                task['file_upload_id'] = file_upload.id

            new_data_fields = set(iter(new_tasks[0]['data'].keys())) if len(new_tasks) > 0 else set()
            if not common_data_fields:
                common_data_fields = new_data_fields
            elif not common_data_fields.intersection(new_data_fields):
                raise ValidationError(
                    _old_vs_new_data_keys_inconsistency_message(
                        new_data_fields, common_data_fields, file_upload.file.name
                    )
                )
            else:
                common_data_fields &= new_data_fields

            tasks += new_tasks
            fileformats.append(file_format)

            if trim_size is not None:
                if len(tasks) > trim_size:
                    break

        return tasks, dict(Counter(fileformats)), common_data_fields

    @classmethod
    def load_tasks_from_uploaded_files_streaming(

View on GitHub (pinned to 0b49e9b539)

Solutions

1. Rename keys in the offending file's tasks so they include at least one key common with the other files
2. Import the mismatched file separately or into a project whose data keys match it
3. Align the label config's $-keys across all files before reimport

Example fix

// before (file B)
[{"data": {"sentence": "hi"}}]  // file A uses "text"
// after
[{"data": {"text": "hi"}}]

new_keys = set(new_tasks[0]['data'].keys()) if new_tasks else set()
if common_keys and not common_keys & new_keys:
    raise ValueError(f"{file_name} data keys {new_keys} share nothing with {common_keys}")

def keys_intersect(task_batch, common):
    if not task_batch:
        return True
    return bool(common & set(task_batch[0]['data'].keys()))

try:
    tasks = FileUpload.load_tasks_from_uploaded_files(project, upload_ids)
except ValidationError as e:
    if 'data key' in str(e).lower() or 'inconsisten' in str(e).lower():
        # identify offending file named in the message and fix its keys
        ...
    raise

When it happens

Trigger: Calling load_tasks_from_uploaded_files (directly or via load_tasks, sync/async reimport, tasks_from_url) with several file uploads whose first tasks have disjoint data-key sets, e.g. file A uses {"image": ...} and file B uses {"text": ...}.

Common situations: Reimporting into an existing project after the label config/data keys changed; mixing exports from different projects; batch-uploading files prepared with different column names (image vs img, text vs sentence).

Related errors

• Task item should be dict
• Unsupported or invalid JSON structure
• Failed to parse JSON file {self.file_name}: {extract_message
• Your label config has more than one data key and direct file
• Failed to parse input file {self.file_name}: {extract_messag

AI-assisted analysis of HumanSignal/label-studio@0b49e9b539 (2026-08-29). Data as JSON: /api/errors/f6e9d833a1108df9. Report an issue: GitHub.