I can't submit my code using the text box now. I can select the issue, language and submit using a file, but I can't submit the source code directly. How can I solve this problem.
Update: After many attempts, I finally located the error, which is caused by an ad blocker called AdGuard.Hope this may help you.
Try to clear the cache.
Thanks for your suggestion. I tried it and it was caused by a sudden update of a web ad blocker I used before.