Resolution is broken, can't be set properly

PC Bug Report
1

I haven’t been able to properly set my resolution since launch. When I go to Graphics settings in options, the only options under Display are “Windowed” and “Windowed (Fullscreen)”. For both options, the Resolution option is greyed out and can’t be adjusted. When playing in Windowed (Fullscreen) mode (5120x1440), there are huge black bars on both sides of the game, and when playing in Windowed mode, mouse tracking breaks and my click register a little above the mouse cursor.

Monitor: Samsung Odyssey G9 Ultrawide
OS: Windows 11
GPU: nVidia 4080 FE (I also tried on a different system with a 2080 TI)

2

I would recommend closing the game, and then deleting your LocalPrefs.txt file where it stores these settings in case it is corrupted.

When you open the game, it will create a new one for you with default settings.

It is located in: “C:\Users\(username)\Documents\Diablo IV\LocalPrefs.txt”

Also, you can go in there and manually edit settings to set whatever resolution you like, and then set the file properties to “read-only” to prevent the game from overwriting things in the future.

It also stores things like the game volume, so if you do set it to read only, it will not allow the game to remember things like your volume settings between sessions.

3

That file doesn’t even exist, the only file in there is LocalPrefs.txt, and the only parameters that relate to resolution have the following values:

DisplayModeFlags “0”
DisplayModeWindowMode “1”
DisplayModeWinLeft “0”
DisplayModeWinTop “0”
DisplayModeUIOptWidth “1024”
DisplayModeUIOptHeight “768”
DisplayModeWidth “5120”
DisplayModeHeight “1440”
DisplayModeRefreshRate “-1”
DisplayModeColorSpace “0”
DisplayModeMSAALevel “0”
Monitor “0”
RenderResolutionScale “1.000000”

I did a full reinstall of the game, that didn’t fix.

4

That is the correct one. I put the wrong name in my post. Apologies.

You can delete that file in case it is corrupted, and the game will create a new one with default values for you.

5

Deleted, still didn’t work, the file was recreated with the same values posted above. I still see black bars on the sides when in Windowed (Fullscreen) mode, and in both Windowed and Windowed (Fullscreen) I can’t modify resolution, it’s greyed out.

Edit: It looks like this is a problem for ultrawide monitors, so far there’s mounting evidence it has something to do with the Samsung Odyssey G9:

https://us.forums.blizzard.com/en/d4/t/cant-change-resolution/42246/13