Discord invite links are set by the server owner and/or moderators. Their expiry date and time also are set by them. If you are unable to join, you need to contact the owner for a new invite link.
I have no way of contacting him though.. thought maybe someone would see this that's already in the discord.
Some servers require a moderator or owner - because regular users wouldn't be able to send you an invite link in the first place. Also - there are a number of discord servers out there (some are private), you'll need more information for us to figure out which one you are referring to.