Hi,
Beginning earlier today, whenever I try to use sudo pacman -Sto download something, I get the following error:
error: multilib: missing required signature error: database 'multilib' is not valid (invalid or corrupted database (PGP signature))
I have already attempted the following solutions:
I tried updating the keys by using sudo pacman-key --refresh-keys. It outputs a bunch of stuff about the keys it is refreshing for 10-20 minutes, but eventually it hangs and I have to force-close it.
I tried to clean my cache by using sudo pacman -Scc(which works fine) and then sudo pacman -Syyu, but I get the error:
error: failed retrieving file ‘multilib.db.sig’ from ``mirrors.jlu.edu.cn`` : The requested URL returned error: 404
error: failed to synchronize all databases (failed to retrieve some files)
But that URL works fine in my browser, and when I remove it from the server list at /etc/pacman.d/mirrorlist, I just get the same error with the next server on the list, which works fine in my browser et cetera.
I tried using sudo rm -R /var/lib/pacman/syncto delete… ok I don’t actually know what that deletes, but somebody said doing that and then sudo -E pacman -Syusolved their problem 
But it just gave me the same 404 as above 
Then I tried doing the above two things again with my VPN off (I live in the northeast of China), but the results were no different.
Lastly, I even tried turning the computer off and then back on. But pacman still gives me same error.
And then I did all of the above again, in order to copy the error messages for you guys
What should I try next? I would… like to be able to download programs again🙏
