When disconnecting a data source in Salesforce Data Cloud, the system checks for active dependencies that rely on the data source. Based on Salesforce’s official documentation (Disconnect a Data Source), the error occurs if the data source has data streams or segments associated with it. Here’s the breakdown:

Key Dependencies That Block Disconnection

Data Stream (Option B):

Why It Matters:A data stream is the pipeline that ingests data from the source into Data Cloud. If an active data stream is connected to the data source, disconnecting the source will fail because the stream depends on it for ongoing data ingestion.

Resolution:Delete or pause the data stream first.

Documentation Reference:"Before disconnecting a data source, delete all data streams that are associated with it." (Salesforce Help Article)

Segment (Option C):

Why It Matters:Segments built using data from the source will reference that data source. Disconnecting the source would orphan these segments, so the system blocks the action.

Resolution:Delete or modify segments that depend on the data source.

Documentation Reference:"If there are segments that use data from the data source, you must delete those segments before disconnecting the data source." (Salesforce Help Article)

Why Other Options Are Incorrect

Activation (A):Activations send segments to external systems (e.g., Marketing Cloud) but do not directly depend on the data source itself. The dependency chain is Segment → Activation, not Data Source → Activation.

Activation Target (D):Activation targets (e.g., Marketing Cloud) are destinations and do not tie directly to the data source.

Steps to Disconnect a Data Source

Delete Dependent Segments:Navigate to Data Cloud > Segments and remove any segments built using the data source.

Delete or Pause Data Streams:Go to Data Cloud > Data Streams and delete streams linked to the data source.

Disconnect the Data Source:Once dependencies are resolved, disconnect the source via Data Cloud > Data Sources.