Error when accessing CRM from code

I'm getting the following error when accessing CRM from code in Azure:

The authentication endpoint AsymmetricToken was not found on the configured Secure Token Service!
   at Microsoft.Xrm.Sdk.Client.IssuerEndpointDictionary.GetIssuerEndpoint(TokenServiceCredentialType credentialType)
   at Microsoft.Xrm.Sdk.Client.ServiceConfiguration`1.Issue(AuthenticationCredentials authenticationCredentials)
   at Microsoft.Xrm.Sdk.Client.ServiceConfiguration`1.AuthenticateTokenWithACSForCrm(AuthenticationCredentials authenticationCredentials, Uri appliesTo, Uri acsEndpoint)
   at Microsoft.Xrm.Sdk.Client.ServiceConfiguration`1.AuthenticateOnlineFederationInternal(AuthenticationCredentials authenticationCredentials)
   at Microsoft.Xrm.Sdk.Client.ServiceConfiguration`1.Authenticate(AuthenticationCredentials authenticationCredentials)
   at Microsoft.Xrm.Sdk.Client.ServiceConfiguration`1.Authenticate(ClientCredentials clientCredentials)
   at Microsoft.Xrm.Client.Services.OrganizationService.CreateUserTokenResponse(CrmConnection connection, IServiceConfiguration`1 config)
   at Microsoft.Xrm.Client.Services.OrganizationService.GetUserTokenResponse(CrmConnection connection, IServiceConfiguration`1 config)
   at Microsoft.Xrm.Client.Services.OrganizationService.ToOrganizationServiceProxy(CrmConnection connection)
   at Microsoft.Xrm.Client.Services.OrganizationService.ToOrganizationService(CrmConnection connection)
   at System.Lazy`1.CreateValue()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.Xrm.Client.Services.OrganizationService.InnerOrganizationService.get_Value()
   at Microsoft.Xrm.Client.Services.OrganizationService.Dispose()
   at Microsoft.Xrm.Client.CrmOrganizationServiceContext.Dispose(Boolean disposing)
   at Microsoft.Xrm.Sdk.Client.OrganizationServiceContext.Dispose()
   at Xrm.wse_Data.GetDatumsWaitingForDataFile(String filename) in C:\Users\XXXX\Documents\GitHub\XXXX\Xrm\Xrm\Data.cs:line 284
   at Scoring.AzureScoring.<FillDataRequests>d__102.MoveNext() in C:\Users\XXXX\Documents\GitHub\XXXX\Scoring\Scoring\AzureScoring.cs:line 4882
System.NotSupportedException: The authentication endpoint AsymmetricToken was not found on the configured Secure Token Service!
   at Microsoft.Xrm.Sdk.Client.IssuerEndpointDictionary.GetIssuerEndpoint(TokenServiceCredentialType credentialType)
   at Microsoft.Xrm.Sdk.Client.ServiceConfiguration`1.Issue(AuthenticationCredentials authenticationCredentials)
   at Microsoft.Xrm.Sdk.Client.ServiceConfiguration`1.AuthenticateTokenWithACSForCrm(AuthenticationCredentials authenticationCredentials, Uri appliesTo, Uri acsEndpoint)
   at Microsoft.Xrm.Sdk.Client.ServiceConfiguration`1.AuthenticateOnlineFederationInternal(AuthenticationCredentials authenticationCredentials)
   at Microsoft.Xrm.Sdk.Client.ServiceConfiguration`1.Authenticate(AuthenticationCredentials authenticationCredentials)
   at Microsoft.Xrm.Sdk.Client.ServiceConfiguration`1.Authenticate(ClientCredentials clientCredentials)
   at Microsoft.Xrm.Client.Services.OrganizationService.CreateUserTokenResponse(CrmConnection connection, IServiceConfiguration`1 config)
   at Microsoft.Xrm.Client.Services.OrganizationService.GetUserTokenResponse(CrmConnection connection, IServiceConfiguration`1 config)
   at Microsoft.Xrm.Client.Services.OrganizationService.ToOrganizationServiceProxy(CrmConnection connection)
   at Microsoft.Xrm.Client.Services.OrganizationService.ToOrganizationService(CrmConnection connection)
   at System.Lazy`1.CreateValue()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.Xrm.Client.Services.OrganizationService.InnerOrganizationService.get_Value()
   at Microsoft.Xrm.Client.Services.OrganizationService.Dispose()
   at Microsoft.Xrm.Client.CrmOrganizationServiceContext.Dispose(Boolean disposing)
   at Microsoft.Xrm.Sdk.Client.OrganizationServiceContext.Dispose()
   at Xrm.wse_Data.GetDatumsWaitingForDataFile(String filename) in C:\Users\XXXX\Documents\GitHub\XXXX\Xrm\Xrm\Data.cs:line 284
   at Scoring.AzureScoring.<FillDataRequests>d__102.MoveNext() in C:\Users\XXXX\Documents\GitHub\XXXX\Scoring\Scoring\AzureScoring.cs:line 4882FillDataRequests filldatarequests:yyyy\20161019_20161020_19_xxxx.csv20161019_20161020_19_xxxx.csv

I can log into CRM using the account that is being used to access CRM in this code, and I can also log into the plugin registration tool with the same account. So how else can I investigate this on the CRM side?

Thanks