Slack Provisioning Error " Unauthorized. Errors reported by the connector : {"Errors":{"description":"invalid_authentication","code":401}}. Error Code: null"
Oct 15, 2025
Okta Integration Network
Overview
Slack provisioning flow fails with the following error visible in the Okta dashboard:
Automatic provisioning of user <user> to app Slack failed: Error while verifying if user <user> exists: Errors during execution: Error executing checkUserExists: Unauthorized. Errors reported by the connector : {"Errors":{"description":"invalid_authentication","code":401}}. Error Code: null
Applies To
- Slack
- Provisioning
- Task Error
Cause
The error invalid_authentication is due to one of the following:
- The Slack administrator credentials used to create the API connection are invalid.
- The Authentication token is invalid.
Solution
- Go to Okta Admin Console and navigate to Applications > Applications > Slack > Provisioning > Integration > click Edit button.
- Click Re-authenticate with Slack. The Slack application opens in a new window.
- Sign in to Slack with valid credentials and click Authorize. The Slack window closes, leading to a return to the Okta Admin Console, and the message Slack was verified successfully appears.
- Click Save.
- Attempt the failed tasks again. Navigate to Dashboard > Tasks. Any failed assignments should appear under Tasks.
- After identifying the failed task for the user that should be retried, click on Retry Selected.
