Help with Exporting EC2 Instance to VM

I'm trying to export an EC2 instance so I can use it locally, but I'm running into some issues. I made sure to hook up the instance with an unencrypted EBS volume, as I copied everything over from an encrypted one, and everything seems to be functioning correctly. However, when I initiate the export using "aws ec2 create-instance-export-task", the task stays in the "active" state for quite a while before switching to "deleted" with a status message saying "Task Cancelled." The only thing I can find in my S3 bucket is a file named "vmimportexport_write_verification.txt" that shows an "Access Denied" error. I've tried searching through all the relevant AWS documentation and even asked ChatGPT for assistance, but I'm still stuck. One potential issue I suspect could be related to the fact that the base AMI might have come from a third party instead of directly from AWS since the instance was set up through a collaboration. The instance is currently in my region, and I can access and manage it without issues.