TypeError: Cannot assign to read only property 'undefined' of object '#', did not find any solution in past posts

URL of experiment: experiment [PsychoPy]

Description of the problem:
My experiment run locally on my computer. It begins to run online, but when it tries enters a loop, it crashes with the error: “TypeError: Cannot assign to read only property ‘undefined’ of object ‘#’”.
There are no empty columns on my csv files, creating a new conditions files does not solve this problem.
does anyone know what can fix this?