Sc_make_link behavior

Hi
I have the same app in two projects
I use sc_make_link
In one case it returns "https://xxxx.xxxxxxx.com/scriptcase91/app/xxxxxxx/app_xx/app_xx.php

In the second project it returns
"https://xxxx.xxxxxxx.com/scriptcase91/app/xxxxxxx/app_xx/
The php file is missing here.

any idea?

thanks