IndexSizeError when running XP online - works fine locally

Hi there,

Description of the problem:
We are designing a Corsi blocks task on Psychopy and are trying to bring it online with Pavlovia. Everything works just fine in the builder but I am now facing with an unknown error message when I try to run it online :

image

I have the feeling it struggles to load the images, for some reasons.

URL of experiment:

Any help would be greatly appreciated !