If you have mistakenly changed a configuration item, roll back immediately. ACM supports querying configuration change history and rolling back configurations.
Here are the steps to view configuration change histories in the ACM console:
Log on to the ACM console, and select the Region as needed in the upper-left corner.
Select Configurations in the left-side navigation pane, enter the configuration information you want to search for, and click the Search button.
In the search result, click More > Historical Versions on the right side to view its change history.
On the configuration history page, click Details to view the configuration value of a specific version. If you need rollback, select the version you want to roll back the configuration to, and click Roll Back.
Note: ACM currently saves change histories of the last 30 days.