Allen-Bradley PanelView Plus is a good machine operator interface. But if you do not set it up correctly, it does not run application automatically at start up. It either shows not finding the application file or not application loaded, as shown in pictures below.
Actually, this was caused by an application setting in panelview plus under start up option. You can set it to load application automatically as shown in steps below:
Load Application with Load Applications button
Access Terminal Setting screen with Terminal Settings button
Select On Start Up run application
On Start Up option, select replace communication at start up and delete log file (optional)
Click on OK buttons all the way to main screen. Reboot the panelview plus, it should run the loaded application at start up.