---
title: "Troubleshooting Slack alerts"
description: "Fix Slack alerts that do not arrive, from the Slack error you see in the test, including channel_not_found, missing_scope, and a bot that is not in the channel."
content_type: "troubleshooting"
product: "alerts"
platform: "TIR"
url: "/tir/alerts/troubleshooting/slack/"
relationships: {"troubleshooting-for":["/tir/alerts/how-to/send-alerts-to-slack/"]}
---

# Troubleshooting Slack alerts

<!-- cspell:ignore xoxb -->

TIR shows a Slack error when you use **Test URL** or **Test Token** in the integration form. A live alert
that fails does so silently, so test again when alerts stop arriving.

| What you see                                              | Likely cause                                                             | What to do                                                                                                                                              |
| --------------------------------------------------------- | ------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------- |
| The test message does not arrive (**Webhook**)            | The webhook URL is incomplete or wrong                                   | Copy the full URL again from **Incoming Webhooks** in the Slack app. It starts with `https://hooks.slack.com/services/`. Check that the channel exists. |
| The test message does not arrive (**Token**)              | The bot has not joined the channel                                       | In the channel, run `/invite @<your app name>`.                                                                                                         |
| `channel_not_found`                                       | The **Channel ID** is wrong                                              | Enter the Channel ID, such as `C12345678`, not the channel name.                                                                                        |
| `missing_scope`                                           | The bot token has no `chat:write` scope                                  | Under **OAuth & Permissions** in the Slack app, add `chat:write`, then install the app again.                                                           |
| Alerts stopped arriving after they worked                 | The webhook URL was regenerated in Slack                                 | Update the **Webhook URL** in the monitoring integration.                                                                                               |
| Messages go to the wrong channel                          | The **Channel ID** is wrong, or the webhook was made for another channel | Check the Channel ID, or create a webhook for the right channel.                                                                                        |
| The bot posts in public channels but not in a private one | The bot has not joined the private channel                               | Run `/invite @<your app name>` inside the private channel.                                                                                              |

TIR also checks the format before it saves. A Slack webhook URL must start with
`https://hooks.slack.com/services/`, and a bot token must start with `xoxb-`. A Channel ID must
start with C, G, or D, followed by at least eight capital letters or digits.

See [Send alerts to Slack](/tir/alerts/how-to/send-alerts-to-slack/) for the full setup.