your launcher chashes when you try to link your account;
nothing happens when you click on the link account button in the browser.
If you have faced an issue, when you can’t link your account in FiveM launcher, try to use different browser.
If you use Chrome, new tab with the link button may close when you close laucher, before you do so, copy link and paste it, for example, in Internet Explorer.
You should be able to link your account via Internet Explorer for sure.
If it didn’t help you, try to disable your antivirus and/or unlink your account. If you still see [Link] button in the launcher, system may still think that your account is linked, so be sure to check it out by following the steps below.
Or you can do it yourself. Copy and paste the thread into the How To Section then click the three dot icons and click bin and it should automatically remove the thread for you.