Unexpected UAC prompt after closing maintainancetool

When I start the maintenancetool for my application and close the maintenancetool directly I get a UAC asking for permission. The maintenancetool  didn't perform any action so I don't expect the maintenancetool to ask for any permission.

When I decline the UAC a process without window/UI stays active in the background using 10% of the CPU. This is really bad because than the end-user can't start the maintainancetool anymore without killing the process manually. 

Any Ideas what might cause this UAC prompt or what "--start-server..." acutally does and how to prevent it?

I included screenshots of the UAC and an error message after decline the UAC. The screenshots where taking from my work PC so sadly the text is in german.