Authorization Request - Internal Error

Hello.  I'm attempting to issue an Authorization Request and am receiving Internal error 500:

(I've x'ed out sensitive information)

Here is the request information:

{System.Net.HttpWebRequest}
Accept: "application/json"
Address: {https://api.cc.email/v3/idfed?client_id=xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx&redirect_uri=https%3A%2F%2Flocalhost%3A8888&response_type=code}
AllowAutoRedirect: True
AllowReadStreamBuffering: False
AllowWriteStreamBuffering: True
AuthenticationLevel: MutualAuthRequested {1}
AutomaticDecompression: None {0}
CachePolicy: {Level:BypassCache}
ClientCertificates: {System.Security.Cryptography.X509Certificates.X509CertificateCollection}
Connection: Nothing
ConnectionGroupName: Nothing
ContentLength: -1
ContentType: "application/x-www-form-urlencoded"
ContinueDelegate: Nothing
ContinueTimeout: 350
CookieContainer: Nothing
CreatorInstance: {System.Net.WebRequest.DesignerWebRequestCreate}
Credentials: Nothing
[Date]: #1/1/0001 12:00:00 AM#
Expect: Nothing
HaveResponse: False
Headers: {Accept: application/json
Content-Type: application/x-www-form-urlencoded
Authorization: Basic xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

}
Host: "api.cc.email"
IfModifiedSince: #1/1/0001 12:00:00 AM#
ImpersonationLevel: Delegation {4}
KeepAlive: True
MaximumAutomaticRedirections: 50
MaximumResponseHeadersLength: 64
MediaType: Nothing
Method: "POST"
Pipelined: True
PreAuthenticate: False
ProtocolVersion: {1.1}
Proxy: {System.Net.WebRequest.WebProxyWrapper}
ReadWriteTimeout: 300000
Referer: Nothing
RequestUri: {https://api.cc.email/v3/idfed?client_id=xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx&redirect_uri=https%3A%2F%2Flocalhost%3A8888&response_type=code}
SendChunked: False
ServerCertificateValidationCallback: Nothing
ServicePoint: {System.Net.ServicePoint}
SupportsCookieContainer: True
Timeout: 100000
TransferEncoding: Nothing
UnsafeAuthenticatedConnectionSharing: False
UseDefaultCredentials: False
UserAgent: Nothing

Any help would be appreciated.

Thanks.

Chris