It would be a message box that blocks the game from loading until you have clicked "OK," so you would have noticed. This means the unlimited-custom-markers.dll is not loaded and I don't know why. I'm testing on the GOG Galaxy build (and it works for me), but as Berlioz22 also experiences the same issue with GOG Galaxy, it does not sound like a Steam-specific problem. Did you all reinstall from scratch or update from Witcher 3 v1.32? I updated to v4.0.0_Hotfix2 from the latter version, maybe some file is left over during the update which makes the dsound.dll load and is missing from fresh reinstalls; however that options seems unlikely. If anyone could PM me their "bin" folder, that might be helpful. And if that does not bring any findings, if someone is willing to let me debug their issue via a remote desktop, let me know. It's a first time install of Witcher 3 (4.0.0). No previous mods of game versions. I'll send a 'bin' folder. Hope it helps. Thank you