Hi Ulises,
I would recommend to terminate this instance and to try to create a new one. I expect that the activate operations will fail with the same error.
Then please move the mouse over the exclamation mark next to the status icon to see the error message? Most probably it will come from AWS. If so, you can get the error code from the message and search by it in http://docs.aws.amazon.com/AWSEC2/latest/APIReference/api-error-codes.html.
Best regards,
Stanimir