I have a Windows 2012 Standard x64 RemoteApps RDWeb portal where I can launch apps. We have one remote app in particular which is RDP (mstsc.exe). Whenever a user launches it, they receive three different prompts--the second one is this alert (shown below).

How can I get rid of this alert? I have other RemoteApps launching as well, and they do not throw errors or alerts like this one. And they are applications with the .exe extension, so I do not understand what is so unique about the RDP RemoteApp that would cause this alert.

One thing perhaps worth mentioning is this particular RDP remote app points directly to the mstsc.exe executable residing on a particular session host/terminal server (as shown in the "From" value of the warning). As such, a gateway server would not be used to load-balance and choose the RDP client launched from a session host at random. This RDP RemoteApp is explicitly associated with one particular terminal server.