Just did a fresh install of 2.4 on a server that has previously hosted FA without other problems than some HTACCESS updates. However, when installing (and when trying to install languages/extensions/etc.), I now get the "Cannot download repo index file." message.
I'm aware of the following post: https://frontaccounting.com/punbb/viewtopic.php?id=6667
I've been able to download files directly pointed to the repo.frontaccounting.eu address earlier today, so I can access that server.