Get "No targets matched selector" when use /msg, /tell, /w commands.

So we updated to the new version of Minecraft, and suddenly we all can't use /msg. When I /msg someone, it just says "No targets matched selector." When I @ everyone it would say <insufficient permissions for selector expansion,> despite being the admin myself. We didn't mess with gamerules as well. We just updated.

Edit: This doesn't happen in local worlds.

Also applies to /w and /tell commands.