Failed to create D3D Device:
This error is normally caused when your desktop resolution is set to a ratio/resolution that the game does not play nice with.
I do see this error commonly with in my work place for some of our clients, the easiest way to resolve this issue is to set you desktop resolution to the same resolution that you have D3 set to. You do not have to set your desktop to the same resolution as you play Diablo 3 in but you must pick a resolution that carries the same aspect ratio as the resolution you play the game in.
It appears to be an aspect ratio issue where you native desktop resolution is not quite 4:3, 16:9, or 16:10.
This seems to cause an issue with D3D creating the device. this is NOT a Diablo 3 issue, this can happen on many apps and is actually a common issue with abstract monitor resolution.
Lets do an example:
If you have your game set to be played on 1280x720 this is a 16:9 aspect ratio. but you have your monitor set to 1360 x 768, its very close to 16:9 aspect ratio, but it is in fact 6 pixels off. this situation will, and can throw the "Could not create D3D device" error.
Here is a wiki link to a table of graphical resolutions so you can pick one for your desktop and Diablo 3 of the SAME aspect ratio, that will make sure you do not see issues.
Edited by GhostlyCrowd#1828 on 6/27/2012 4:47 PM PDT
This didn't work for me. My issue is that I uninstalled Diablo III to try to change what drive it was installed to. It came up with this error after I tried to run it. So I uninstalled it from that drive and put it back on the drive were it was originally located. I still get this error. I have uninstalled and re installed in numerous times but it still has an issue with creating the D3D device
Edit d3prefs.txt and change "DisplayModeWindowMode" to "2".
setting it to "0" Will place it in full screen mode, 2 will place it in windowed full screen, and 1 will place it in windowed.
options 1 and 2 will cause the D3D error if you have some sort of non standard monitor desktop resolution running like i sated in the first post.
Its derpy programming, Blackberry's sync software has this exact same issue when you run a weird desktop resolution.
Edited by GhostlyCrowd#1828 on 7/6/2012 9:34 AM PDT
This fix worked for me.
I have a y580 laptop, 660m nvidia (306.02 driver), and copied over d3 files (from "C:\Program Files (x86)\Diablo III\)...started up, worked fine.
Then, I plugged in a Plugable (brand name) DisplayLink USB 2.0 to DVI adapter and ran some movies through it to test my monitor. Worked fine.
Then tried to start diablo again, and got the 'creating d3d device' error. Tried reinstalling Diablo III from scratch, tried reinstalling drivers, tried deleting D3Prefs.txt file.
Fix: changed this line:
works fine now.
i just had this too and it had nothing to do with the resolution.
i had an HDMI cable that i just plugged in to a video converter, which i did not unplug once i finished using the converter.
after i unplugged it, Diablo started.
add this to the FAQ or something...
anyone can tell me in (normal language) how to do this?. I did delete my third party software did everything you guys did but i can put my mode of my screen on HDMI etc even did it on (right click, properties etc... to change resolution) Didnt worked i tried them all, any help?
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