Problem Adding Existing Application

I'm new to Powerbuilder however my company has been using it for a long time. I'm having an issue adding a new target with an existing application. When I try to add an existing application I just get a blank screen to choose from. It also causes me to no longer to be able to add a new application unless I close and reopen Powerbuilder. Below is what I see when I try to add an existing application. Any help is appreciated. Thanks