Troubleshooting "Salesforce User Isn't Connected to Slack" Error in Slack Flow Core Actions

Cause 1: Salesforce App Not Properly Installed in Slack

The Salesforce app must be installed in the Slack workspace where messages are being sent. If the Salesforce app was removed, reinstalled, or if workspace permissions changed, the connection between Salesforce and Slack breaks.

Resolution: Reinstall the Salesforce app from the Slack App Directory in your Slack workspace. After reinstalling, reconnect the app to your Salesforce org by following the in-app prompts.

Cause 2: User Connection Between Salesforce and Slack Is Broken

Each Salesforce user account that runs a flow containing the Send Slack Message action must be individually connected to Slack. If the user's Slack connection is expired or was revoked, the action fails.

Resolution: Reconnect the Salesforce user to Slack by navigating to the user's Salesforce profile settings, locating the Slack integration section, and re-authenticating to reestablish the connection between the Salesforce user and their Slack account.

Cause 3: Incorrect Slack Workspace ID or Conversation ID Provided

The Send Slack Message action requires valid input parameters, including a Slack Workspace ID and a Slack Conversation ID (the channel or user conversation to send the message to). If these IDs are incorrect — for example, if they were copied from a different Slack workspace or an invalid conversation — the action fails with this error, even if the app and user connections are valid.

Resolution: Review the input parameters passed to the Send Slack Message action in your flow. Verify the correct Slack Workspace ID and Slack Conversation ID by referring to the Send Slack Message Action documentation linked in Additional Resources below. See Send Slack Message Action for input parameter details.