Jagged fonts and images in AIR

AIR installation dialogs and AIR applications (in this case juiceboxbuilder pro) have jagged fonts and graphics. This happens on my mac mini with a 4k monitor via HDMI. It does not happen on my MacBook Pro (Retina, 13-inch, Late 2013). The problem is specific to AIR and its applications, for the rest everything is fine and smooth. Does anyone have an idea how to remedy this problem?