Splash Screen does not change

If I select an PNG file, the splash screen does not change.

So this is an issue I am currently experiencing with RealWorld Paint. I am running version 2013.1 on a Windows 10 machine with version 20H2 (OS Build 19042.1387). I go ahead and go to "About RealWorld Paint..." in the "About" menu. I am able to change the name of the application, but for some reason, it won't accept the PNG file. I made a custom PNG file using the application and want to use it as the splash screen. Can anyone help solve this issue?