troublemaker is in the right with this - the CORS settings are incorrect.
Short explanation: The launcher runs on the URL
https://launcher.larian.com and tries to send a request to
https://larian.com/api/. While both URLs include 'larian.com', the URL 'launcher.larian.com' is a different subdomain, which is why there would need to be specific headers set in the request to enable communication between those subdomains.
Basically nothing that can be fixed on the player side, but rather has to be fixed by Larian.
P.S.:
@troublemaker: How did you find the URL of the launcher? (As DevTools do not work in the launcher itself) Did you wireshark it or something?
