foobar Google - Error 403 permission denied - programming challenge
I also faced the same issue. You can solve this by closing the current foobar session and opening a new in another tab.
This will definitely solve this problem.
I am doing a challenge for Google FooBar, and am having trouble submitting my code.  My code is correct, and I have checked my program output against the answers provided by Google, and my output is correct.  However, when I try and submit, I get a Error 403: Permission denied message.  I cannot submit feedback either because I receive the same error message.  Does any one have any advice?