docusign 500 error when trying to Create Envelope

I am using C# docusign JWT SDK to authenticate. I am able to authenticate and get an access token back where I am able to successfully call GetUserInfo to get account information, but when I create an envelope from the downloaded example, and send that to the CreateEnvelope(account,envelope), it is generating a 500 error message with Stack Trace error…
“at DocuSign.eSign.Api.EnvelopesApi.CreateEnvelopeWithHttpInfo(String accountId, EnvelopeDefinition envelopeDefinition, CreateEnvelopeOptions options)”

My scopes are “signature” and “impersonation”

What am i not doing correctly?

Thanks