I'm able to reproduce it reliably btw, this error comes up (https://v6p9d9t4.ssl.hwcdn.net/html/7179911/regions/village just returns the error XML instead of the game HTML) always on the first time I load the page after restarting firefox or chromium (which I freshly installed just to attempt to reproduce this in another browser so it can't be caused by addons). But somehow after opening the game's itch page in a new tab again after I'd gotten this error, it was able to access my save again? Not the original one of course anymore but a newer one after I restarted (decided to do so cos I was so addicted and the export/import feature at least allows me to take manual backups). Very confusing.