Since we receive alot of 'error messages' we like to introduce a format for you to use when posting one. This format needs to be used and without providing the proper information we can't offer you the right support. The form you will be using is as follows;
GTA V version?
Up to date?
Legit or Pirate copy?
Did you try to disable/uninstall your Anti-virus?
Did you try to delete caches.xml and try again?
GTA V folder screenshot
GTA V/update/x64/dlcpacks screenshot
Filepath to FiveM folder
FiveM Application Data folder screenshot
Also add what you already tried so far.
If you aren't able to provide any of the above things don't worry but tell us why you are unable to supply proper info.
FiveM Support team.