Dataflow Not Running with dynamic variables from Variable Library in Fabric Pipeline

Hi Everyone,

I'm working with Microsoft Fabric pipelines and using a Variable Library to dynamically assign values to the Dataflow activity, specifically for workspaceId and dataflowId.

My Setup:

• I've created a Variable Library with the following variables:

  • env: contains the Workspace ID (GUID)

  • movex_customers: contains the Dataflow ID (GUID)

  • dataflow_type: contains the value "DataflowFabric"

  • 

In the pipeline Dataflow activity:

• Workspace ID:
  @pipeline().libraryVariables.env

• Dataflow ID:
  @pipeline().libraryVariables.movex_customers

• 

The Problem:

When I use these variables, the Dataflow activity fails with the following error:

{
  "error": {
    "code": "InvalidRequest",
    "message": "Unexpected dataflow error"
  }
}

Fabric doesn't know it should treat the activity as a Dataflow, so it throws a generic internal error instead of a clear validation failure. This error goes away only when I add the following field to the activity configuration manually in JSON view:

"dataflowType": "DataflowFabric"

However, the Fabric pipeline UI does not expose a field for dataflowType when using dynamic inputs — only when selecting a Dataflow statically.

What I’ve Tried:

1. Variable substitution via expression:

   • Created a variable: dataflow_type = "DataflowFabric"

   • Referenced in activity: @pipeline().libraryVariables.dataflow_type

   • → Field still missing in UI or has no effect

2. Set Variable / Script activity workaround:

   • Used a Set Variable or Script activity to define:

     resolved_dataflow_type = "DataflowFabric"

   • Referenced: @variables('resolved_dataflow_type')

   • → Still not picked up; there's no place to plug it in via UI

3. Hardcoding works:

   • Manually typing Workspace ID and Dataflow ID → activity runs successfully

   • Adding dataflowType via JSON works

   • When dynamic expressions are used for IDs and dataflowType is not set, it fails with “Unexpected dataflow error”

What I'm Looking For:

• Why is Fabric not recognizing the activity as a DataFlow?

• How can I dynamically set dataflowType = "DataflowFabric" when using a Variable Library?

• Is there a hidden property, advanced field, or workaround to inject this value in the UI?

• Is there a future update planned to make dataflowType configurable from the designer?

Happy to share screenshots or test results if needed.

Thanks in advance!