The "cannot decode dynamic from flatmap" error message typically occurs when there is a mismatch between the remote state that Terraform expects to find and the actual state stored in the backend.
To resolve this error, you can try the following steps:
1. Verify that your remote state backend is configured correctly and is accessible. Ensure that your backend configuration includes the correct credentials, endpoints, and other configuration options required for your specific backend.
2. Run the terraform init command to ensure that your local Terraform environment is properly synced with the remote state backend. This command will download the latest state from the backend and update your local state accordingly.
3. Run the terraform refresh command to refresh the state of your Terraform resources. This command will compare the current state of your infrastructure with the state stored in the remote backend and update your local state file accordingly.
4. If the above steps do not resolve the error, you may need to manually edit your state file to remove the problematic resource. You can use the terraform state rm command to remove the resource from your state file.
However, be careful when modifying the state file manually, as any mistakes could cause further errors or data loss.