So i was debugging code with long print calls.
And then i got " JSON error: expected value at line 1 column 1, please double check your session and csrf config. JSON error: expected value at line 1 column 1, please double check your session and csrf config"

But one the website my code is working.

Minimal example that produces the error: ( on execises 26 in python3)

from typing import *
class Solution:
    def removeDuplicates(self, nums: List[int]) -> int:
        print(f'nums are now {nums} and u')
        return 1