Interactive Video in .MOV format : Only showing and playing in the PC on which its been Built

We are facing a strange situation

We are building an interactive Video Training module.

This consists of several videos rendered in .MOV / H.264 and linked using interactive level design in UE4.23

When we play the entire build in the PC on which this has been Built, the following play well :
1. Interface
2. The linked videos

When we play the build in another PC, the following play Only

  1. Interface

The Interface animations and the attached video sounds all play in other PC s BUT the linked Videos do not play.

However, in the PC on which this project has been built, everything plays well.

So this begs the question: Are we doing something wrong? Or have not configured the UE 4 properly?