This helped. Thank you, Manuel!
Do you guys need any more information from me, so you can check this? Let me know
Same happens to me. The regex stops working.
I did some investigation and found:
Looks like the reason for this is an invisible “Zero-width space” (%E2%80%8B) characters get added to the requested URL somehow.
If I copy a URL from 404 log page and then URL-Encode it, I get these characters in the URL: %E2%80%8B
Of course, the regex would not match those characters.
Thanks, Tom.
Random folder name can be cracked by a brute-force attack. It should not take a lot of attempts.