Online experiment: image not showing and not progressing on loop

URL of experiment:

Description of the problem: My experiment initializes and runs up to the 1st (practice trial) then gets stuck with 2 issues.
First, an image is supposed to display before the fixation cross. (A) no image is shown during the time-period, it just progresses normally to the fixation cross.
(B) this is followed by an inter-trial interval window that just displays some text. The text displays fine, but the experiment gets stuck there. The loop does not progress onto the next trial.

This only happens online, and does not happen when done locally.