Unable to click "Create database migration task" on the console

There are several potential reasons why the "Create migration task" button might be greyed out in the AWS DMS console:

1. Check if the user creating the endpoint has the necessary permissions. The IAM user needs appropriate permissions to access AWS DMS and create tasks.

2. Verify that all required fields in the task creation form have been completed. Missing information in any required field can prevent task creation.

3. Ensure that your source and target endpoints are properly configured and that the connection tests were successful for both endpoints.

4. Check if you've properly configured the task settings, including migration type, target table preparation mode, and other required options.

5. Verify that you've specified the table mappings correctly. If you're trying to migrate views rather than tables, make sure you've specified the object-locator as "view" or "all" in your table mappings.

6. You might have reached the resource quota for migration tasks in your account. AWS DMS has service quotas that limit the number of resources you can create.

7. There might be an issue with the replication instance, even if it shows as "available." Try refreshing the console or checking if there are any notifications or alerts related to your replication instance.

If the issue persists after checking these items, you may need to contact AWS Support for further assistance.
Sources
Creating a task - AWS Database Migration Service
Troubleshooting migration tasks in AWS Database Migration Service - AWS Database Migration Service
Create a migration task for a MariaDB database - Database Migration Guide
CreateDataMigration - AWS Database Migration Service