"Butler could not run your rule," but it did.

[Jay Rennemeyer]

I randomly get emails from Butler saying that it couldn't run a rule that posts a message in a Slack channel, even though the rule runs successfully and posts to Slack. I checked the Activity Log and it doesn't list any warnings or errors – everything appears to have run correctly.

What could be causing these emails?

[Mat]

Hi Jay,

The error you received is due to our Automation runs hitting the rate limit threshold which happens sometimes when a rule is meant to perform a lot of actions at once. 

Rules affected by this error will automatically be retried by our Automation tool after waiting for a cooldown period. This is the reason why the rules finish successfully after some time despite the error message. 

Here's more information on the quotas and limits:
https://support.atlassian.com/trello/docs/butler-quotas-and-limits/