An error happens when migrating because one or more features are not activated at the destination. You will get an error message like:

The feature failed to activate because a list at 'Documents' already exists in this site

Could not activate feature because of the following error: There can only be one instance of this list type in a web. An instance already exists.

This error occurs when a feature is required for the migration to execute correctly or to warn that a feature does not exist at the destination.

You can activate existing features at the destination and restart the migration. See how to activate features with Sharegate.

To activate features from SharePoint, go to your site or site collection settings and select Manage Site Features or Site Collection Features.

Once on the Features page, you can activate or deactivate all the features you want by clicking on Activate or Deactivate.