When you use the SFTMIME command within scripts or batch files, it is important to understand that console redirection of output in Microsoft Application Virtualization 4.5 has changed from previous versions.  For example, let's say you do the following:

1. From a 4.5 version of the App-V client, make sure at least one application has been published or streamed to the client.
2. In an elevated command prompt, navigate to the directory where the App-V client is installed (defaults to C:\Program Files\Microsoft Application Virtualization Client).

Full Article