I’ve tried clearing my DNS cache, changing DNS settings, removing all files in the AppData cache for FiveM and all the server jsons in the server folder.
I’ve also restarted the client several times to no avail. Something might be going on that’s affecting lots of people?
You need a clean GTA V installation in order to run FiveM, your installation folder contains modifications which shouldn’t be there which indicates you either used modifications in the past or you are trying to use them right now.
Please remove your modifications and/or re-install GTA V in order to make sure you have a clean installation.