MongoDB CDC - org.apache.kafka.connect.errors.DataException: Invalid value: null used

Hi all,

I try to configure an Eventstream in Fabric.

The source is a MongoDB Atlas instance. I use the standard Fabric "MongoDB CDC Preview" Connector.

In the runtime log, I receive the following failure message:

Task: '617B3313-4F00-4079-BEAF-C3F03C966513-task#0' failed. Details: org.apache.kafka.connect.errors.DataException: Invalid value: null used for required field: \"collection\", schema type: STRING"

Currently, I do not see how to identify the source of the problem.

Any idea or hint to dig into the problem?

Thanks

Rainer

Full log

{
    "ErrorCode": {
        "value": "Task: '617B3313-4F00-4079-BEAF-C3F03C966513-task#0' status to FAILED",
        "type": "string"
    },
    "TimeGenerated": {
        "value": "2026-01-20T08:50:56.376171Z",
        "type": "datetime"
    },
    "Level": {
        "value": "Error",
        "type": "string"
    },
    "Category": {
        "value": "Error",
        "type": "string"
    },
    "ResourceId": {
        "value": "",
        "type": "string"
    },
    "SubscriptionId": {
        "value": "",
        "type": "string"
    },
    "ResourceGroup": {
        "value": "",
        "type": "string"
    },
    "JobName": {
        "value": "",
        "type": "string"
    },
    "OperationName": {
        "value": "",
        "type": "string"
    },
    "Status": {
        "value": "Error",
        "type": "string"
    },
    "Source": {
        "value": "",
        "type": "string"
    },
    "TypeProperty": {
        "value": "Error",
        "type": "string"
    },
    "DataErrorType": {
        "value": "",
        "type": "string"
    },
    "ErrorCategory": {
        "value": "Error",
        "type": "string"
    },
    "BriefMessage": {
        "value": "",
        "type": "string"
    },
    "Message": {
        "value": "Task: '617B3313-4F00-4079-BEAF-C3F03C966513-task#0' failed. Details: org.apache.kafka.connect.errors.DataException: Invalid value: null used for required field: \"collection\", schema type: STRING",
        "type": "string"
    },
    "FromTimestamp": {
        "value": null,
        "type": "datetime"
    },
    "ToTimestamp": {
        "value": null,
        "type": "datetime"
    },
    "EventCount": {
        "value": 0,
        "type": "long"
    },
    "GroupSize": {
        "value": 1,
        "type": "long"
    }
}