My today's Leads is completely blank. As for step 101, here is how I type in "https://webto.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8%22method=%22POST%22&old=00D4T000000DeNb&first_name=En-Chi"
MaxzPlace
Help Forum
Sorry you're stuck but there's almost always a pretty easy fix! Do NOT try to start all over again, uninstall Max's Pitch Package, etc. That can make it worse. There's a 95% chance the same snag/fix is listed & answered in the Help FAQ. But if you can't find it there, post your problem here.
Make sure you post in the right category below & be sure to include a screencap showing the issue!
Ok, so computers are super-picky. You have to get every single character right for this part.
In the URL you're showing, you typed "old" (like old person) instead of "oid" (like Org ID). Change the "l" to an "i" and it will work