Hi there,
Sorry to hear about this!
My first thought is that this may be a permissions issue, and it would be worth right-clicking on the Launcher and selecting Run as Administrator. If you’re on Steam, you could instead try navigating to \Steam\steamapps\common\Last Epoch, right-clicking on Last Epoch.exe, switching to the Compatibility tab, and enabling Run this program as an administrator.
That said, if it was caused by Windows, I’d expect to have seen more reports of this. You could also try adding Last Epoch as an exception in your anti-virus program.
An alternative to troubleshooting this is modifying the graphics .ini file directly yourself. I’ve just noticed that this file appears to no longer list the various levels of each setting. I’ll ask the team about this and see if we can add that back in a future update.