Pipe 'Slack Notify' throws 'invalid_payload' error

[Hasan Toprakkaya]

We tried every example on Slack Notify pipe but we always got the error message "HTTP Response: invalid_payload"

Example pipeline;

image: atlassian/default-image:3
pipelines:
default:
- step:
script:
- pipe: atlassian/slack-notify:2.0.0
variables:
WEBHOOK_URL: $WEBHOOK_URL
MESSAGE: 'Hello, world!'

The error message;

Status: Downloaded newer image for bitbucketpipelines/slack-notify:2.0.0
INFO: Sending notification to Slack...
INFO: HTTP Response: invalid_payload
✖ Notification failed

Any suggestions to solve this problem? 

[Hasan Toprakkaya]

Ok. We figured it out.

We used the Slack's old Incoming WebHook URL and because of that we got this error message.

Now, we created an app on Slack and enabled the WebHook and use that WebHook URL and it worked.