Crash after installation completion when optional section is not selected

Particularly, i have used three sections in an installer in which two are optional, one compulsion. When i don't select particularly one optional section , the installer works fine until the installation complete at installation page, after then the app crashes.

I actually cannot trace what exactly is the reason behind it?
Please provide the probable reasons behind it and their solutions if possible.

Thanks i advance.

We need more information, a minimal example script perhaps...