Help needeed / How to considerably reduce weight of my file Paths.js

Hi, 

I have built a (very) long training in storyline (18 scenes containing between 15 and 20 slides each with texts, images, and some videos) and I have difficulties reducing the weight of its paths.js file (5,2Mo and it should not go over 2Mo to match the LMS tech. requirements)

Do you have tips to reduce it, pleaze? (because I do not even know what this files contains- is it about slides' layouts?