Dynamics CRM 2016 Generate Proxy with CrmSvcUtil

Hello,

Im trying to run the svcutil (like previous versions) like;

CrmSvcUtil.exe /url:http://<serverName>/<organizationName>/XRMServices/2011/Organization.svc /out:<outputFilename>.cs /username:<username> /password:<password> /domain:<domainName> /namespace:<outputNamespace> /serviceContextName:<serviceContextName>

But I get the following error:

"Unable to Login to Dynamics CRM

Exiting program with exception: Connection to CRM is not established. Aborting process.
Enable tracing and view the trace files for more information."

I've turned on tracing but without success... I've tried without user and pass and with all different admin accounts.

Do you have any suggestions?