tl;dr: remove special characters from your billing info if you get a Page Not Found window when paying for a subscription with PayPal Hey, I'm posting this because it was an issue I was having and I couldn't figure it out for several days. I eventually ended up figuring out the cause of my specific issue, and it might help others. Basically, when attempting to change to a paid subscription for Roll20, I was trying to pay with PayPal. Left side was my address info, right side the amount and the payment method/PayPal button. When the PayPal button was clicked, it opened a new window as always (the one that opens PayPal and asks you to confirm). However, the new window was another Roll20 page that just said "Page Not Found" and such. I did all the browser updating, resetting of cookies, updating drivers, etc., but nothing was working. I contacted support thinking it was maybe a bad link between PayPal and Roll20 and so had them remove the link in order to re-link, but that didn't fix it either. On a hunch, I opened the console and found an error that seemed to be saying there was a character it didn't like and couldn't verify or some such. I removed the "#" character I had placed in front of a room number in my address. Poof! No more problems and PayPal checkout worked flawlessly. Also, this issue was specifically only when trying to upgrade my subscription tier. When I tried with something in the marketplace, the PayPal window opened normally. Even with the # character.