Saved app did not run

Good day,

I am using a portable edition of "APK Editor Studio", I installed latest version of Java, then when editing, I only changed the title and icon, but after installing the app, it did not run at all.
I also tried that the same app, just open it and save it without any changes, it also did not run.

What could I do to make the saved app work fine?

Thanks a lot,