Bad request. The api version in the query string is not supported using Service Bus Explorer 2.6.1.0

Question

I get the following error using Service Bus Explorer 2.6.1 when I try to connect to Service Bus 1.1 installed on another server:

<14:38:36> Exception: The remote server returned an error: (400) Bad Request. The api-version in the query string is not supported. Either remove it from the Uri or use one of '2012-03,2012-08,2013-04,2013-07'..TrackingId:ec6d38ba-866b-4e44-9fbd-1a21a03dc3e8_GWIN-VM77MKIHMEG,TimeStamp:11/04/2015 10:37:54

Used string:

Endpoint=sb://SERVER/HelloWorld;StsEndpoint=https://SERVER:9355/HelloWorld;RuntimePort=9354;ManagementPort=9355;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=ekDH5AYdCqXlzetx+5PoLqrcEUeRaqqunRpmUN5Ao4I=

Does anyone know how to fix this error?

Yours faithfully,