You will get the following error when creating Message Buffer possibly because the Issuer Name is not properly configured in your Service Bus namespace. 

{"The token provider was unable to provide a security token. Error:Code:401:SubCode:T2001:Detail:The issuer does not exist, or the secret or signature is invalid."}
    [System.IdentityModel.Tokens.SecurityTokenException]: {"The token provider was unable to provide a security token. Error:Code:401:SubCode:T2001:Detail:The issuer does not exist, or the secret or signature is invalid."}
    Data: {System.Collections.ListDictionaryInternal}
    HelpLink: null
    InnerException: {"The remote server returned an error: (401) Unauthorized."}
    Message: "The token provider was unable to provide a security token. Error:Code:401:SubCode:T2001:Detail:The issuer does not exist, or the secret or signature is invalid."
    Source: "Microsoft.ServiceBus"
    StackTrace: "   at Microsoft.ServiceBus.TokenProvider.ThrowException(String message, Exception innerException)\r\n   at Microsoft.ServiceBus.TokenProvider.GetAccessTokenCore(String appliesTo, String requestToken, String simpleAuthAssertionFormat, TimeSpan timeout, String& expiresIn)\r\n   at Microsoft.ServiceBus.TokenProvider.GetHttpAuthAccessTokenByAssertion(String appliesTo, String requestToken, String simpleAuthAssertionFormat, TimeSpan timeout)\r\n   at Microsoft.ServiceBus.SharedSecretTokenProvider.OnGetHttpAuthToken(String appliesTo, String action, TimeSpan timeout)\r\n   at Microsoft.ServiceBus.TokenProvider.GetHttpAuthToken(String appliesTo, String action, TimeSpan timeout)\r\n   at Microsoft.ServiceBus.HttpBufferClient.AddTokenToRequest(HttpWebRequest webRequest, TransportClientEndpointBehavior credential, String action)\r\n   at Microsoft.ServiceBus.HttpBufferClient.PutMessageBuffer(MessageBufferPolicy messageBufferPolicy)\r\n   at Microsoft.ServiceBus.HttpBufferClient.CreateMessageBuffer(Transpo
rtClientEndpointBehavior credential, Uri messageBufferUri, MessageBufferPolicy messageBufferPolicy)\r\n   at Microsoft.ServiceBus.MessageBufferClient.CreateMessageBuffer(TransportClientEndpointBehavior credential, Uri messageBufferUri, MessageBufferPolicy messageBufferPolicy, MessageVersion messageVersion)\r\n   at Microsoft.ServiceBus.MessageBufferClient.CreateMessageBuffer(TransportClientEndpointBehavior credential, Uri messageBufferUri, MessageBufferPolicy messageBufferPolicy)\r\n

Make sure the Issuer Name that was configured from the Azure Dashboard is exactly the same in your code.

If you happen to experience an error like

"Error 1001. Exception occured while initializing the installation. FileNotFoundException: Could not load file or assembly c:\\windows\system32\files\aa" while adding custom parameter in custom action in MSI installer. This must be because you have not configure properly the custom property.If you should have more than 1 parameter, all must have backslash except for the last one (e.i /targetDir="[TARGETDIR]\" /customConfig="[CUSTOMCONFIG]" )

It's hard to know in an instant which files are still checked-out to who.

Below is the command to do this. 

tf.exe status "$/[your project]" /user:* /s:https://[tfs server] /recursive /login:[username],[password] > c:\tfsStatus.txt