Hi Nick,
No, I can't create instances in your AWS account.
When you tried to create the SolMan 7.2 instance in SAP CAL, first a placeholder was created . Then the creation in AWS failed (the first error message) and therefore only the placeholder stayed, a solution instance in status Initial. Meanwhile the SolMan 7.2 solution was updated and the placeholder was invalidated. Consequently if try to activate the same placeholder you will get the second error message.
To continue you will have to remove the placeholder by terminating the solution instance in SAP CAL. Then go to Solutions, select the SolMan 7.2 solution and choose Create Instance.
Best regards,
Stanimir