Yeah, so I tried Jacob1's Mod and still giving me a lot of 403: Forbidden errors please help me because it's getting annoying!!! I'm done with TPT for this week, i'm not playing it again until it becomes fixed.
403 errors sounds like it's on your connection end. We tend to get nginx 500 errors (server side issue) though. Try checking whether you have any network restrictions like firewalls or website blacklistings. This usually happens in school networks.
Did you take the advice suggested in the other thread about logging out and back in? How often do you get 403 errors? Is it only when doing stuff like uploading saves, or just with the save browser?
It's almost certainly an issue on your side though. I would suggest logging out and back in. If that doesn't work, you may need to try looking at your windows firewall / antivirus / router settings to see if they are blocking it.