I have a setup file but as you can see it says that the file is not available on http server! so yeah the server is down but the download one bcs the web page is up!
Viewing post in Itch.io App Download Error
Someone else was talking about some software being down and not allowing creators to submit installable files. This probably means there's some third party software down that itch relied on for installations. That also may be happening but idk my own experience suggests the app download server is also inaccessible as a result for some reason but that also may just be a weird cascading effect. Either way it's a server side issue. Not much can be done.