For what is worth, I have been trying to get this game working since may of 2026 to no avail, I'm one of the modders for this game, I made the I of the Dragon Rebalanced mod and I can't work on it anymore until this issue is fixed, as I can't test my work, so anything that can help regarding this issue is going to be deeply appreciated.
My experience is different. Proton 11 and experimental don't react to mouse clicks, proton 7 and 9 have the game crash when the main menu is about to load, proton 8 and 10 have working mouse clicks. I didn't need to edit the registry for this. And these results are with wiping the prefix when changing proton versions.
Additionally, when making the prefix with proton 10 and then moving to 11 the mouse clicks would remain functional in proton 11.
@simifor that is very interesting, thanks for sharing, I will try making the prefix with 10 then moving to 11, if that works I will be able to continue with my modding efforts while hopefully this issue gets resolved eventually
opening it with proton 10 has working mouse in the main menu but the bindings are still wrong in game, but it is some progress, by wrong I mean they trigger keyboard inputs like middle mouse triggering the key 4 and zooming, its hard to debug which keys are being triggered, you can open the game console command by pressing the key left to the 1 on the left side of the keyboard 5 times very quickly, then write Commands, to see all the console commands, I didnt find one useful for this but who knows
I'be merged useful data from the comments into a suggested fix.
The I of the Dragon (279720) – broken mouse buttons due to bad DirectInput instance numbers
Mouse buttons work fine in the UI but do nothing (or cause a crash) once you’re actually in the 3D world. This has been consistent across a bunch of Proton versions when you wipe the prefix each time.
| Proton | Result |
|---|---|
| 7 | Crashes right before main menu |
| 8 | Mouse clicks work |
| 9 | Crashes right before main menu |
| 10 | Mouse clicks work |
| 11 / Exp | Clicks are completely ignored |
Interesting side note: if I create the prefix with Proton 10 and then switch to 11, the clicks keep working. So something is getting written into the prefix that later versions still respect.
In dlls/dinput/mouse.c → mouse_enum_objects() the instance numbers are assigned like this:
// Axes
DIDFT_MAKEINSTANCE(0), // X
DIDFT_MAKEINSTANCE(1), // Y
DIDFT_MAKEINSTANCE(2), // Wheel
// Buttons just keep counting upward
DIDFT_MAKEINSTANCE(3), // Button 0
DIDFT_MAKEINSTANCE(4), // Button 1
DIDFT_MAKEINSTANCE(5), // Button 2
...
Instance numbers in DirectInput are supposed to be per object type. Axes and buttons should each start at 0. Continuing the counter across types is wrong, and this game (like a lot of older DirectInput titles) ends up reading the wrong button codes because of it.
Different Wine major versions change enough of the surrounding dinput/HID setup that the same bad numbers sometimes crash and sometimes just silently map to the wrong buttons.
Just restart the button instances at 0:
.dwType = DIDFT_PSHBUTTON|DIDFT_MAKEINSTANCE(0), // Button 0 (was 3)
.dwType = DIDFT_PSHBUTTON|DIDFT_MAKEINSTANCE(1), // Button 1 (was 4)
.dwType = DIDFT_PSHBUTTON|DIDFT_MAKEINSTANCE(2), // Button 2 (was 5)
.dwType = DIDFT_PSHBUTTON|DIDFT_MAKEINSTANCE(3), // Button 3 (was 6)
.dwType = DIDFT_PSHBUTTON|DIDFT_MAKEINSTANCE(4), // Button 4 (was 7)
Five number changes. That’s it.
This matches what the game expects and what real Windows mice report. Once this is fixed the whole “create prefix on 10 then jump to 11” workaround should become unnecessary.
Happy to test a build with the change if anyone puts one up.
I would appreciate if we didn't get AI suggestions, I already tried to solve this myself with AI for months before ever asking here, and it took me nowhere.
@FokkusuES Could you check Proton Experimental? It has some changes that hopefully fix the issue.
Yes, omg it works! The inputs all work correctly! @codeweaverwill
There are still minor graphical glitches known in this game with the flying carpets and stuff but thats nothing to worry about, the control issues that made it unplayable are fixed finally and I can finally continue my modding work of this game, thanks you so much to everyone that worked in this experimental fix
Shall I mark this closed? I'm not familiar with how these threads work
There are still minor graphical glitches known in this game with the flying carpets and stuff
Good call. I initially thought the carpet design was charming old game jank, but I've noted the graphics issue to investigate and yell about it eventually™. For now, adding PROTON_DXVK_D3D8=1 %command% to the launch options should quick fix the carpet.
Shall I mark this closed? I'm not familiar with how these threads work
Leave it open, I'd think. Though @kisak-valve will know better :)
Good luck and enjoy the modding!
yea that did fix the graphical issues, thanks you!
proton experimentalx1 2026-08proton 11.0x1 2026-07PROTON_DXVK_D3D8=1x1 2026-08PROTON_DXVK_D3D8=1 %command%x1 2026-08
Compatibility Report
System Information
I confirm:
Symptoms
Mouse inputs being read as keyboard buttons 2 3 4 at dinput8 on main menu, in the game inputs are also incorrect for keyboard and mouse but is difficult to check as I can't get past of the main menu without a mouse in this game. If we set dinput 8 to native, the game crashes, in proton 7.x versions its possible to use the mouse buttons correctly more or less but its so laggy is unplayable, possibly due to high DPI mouse with high polling rate.
Reproduction