CrossOver's default setting for the Steam app uses a Windows XP bottle. Big Picture Mode only works on Windows Vista or later. If you open the Wine Configuration and change Steam's Windows version to Vista or later, you can then click Big Picture Mode and it will try to launch. For me I get a failure at this point. A pop up says "Fatal Error, Error: CreateRenderTargetView failed, can't create D3D Window" and then second pop up, "Error, Failed creating window/d3d surface for Big Picture". I'm not sure where to go from here, but I'll play around with some settings. Hopefully you can solve it too.
I just re-installed steam on a win7 bottle to try to solve this exact problem, but it still thinks I'm in XP. How do I convince steam we're running in XP? I've not used wineconfig or anything like that before.
Also, I'd love to hear if you've solved your Big Picture Mode problems.
Same problem, I just did a fresh install of Steam in a Windows 10_64 bottle and according to the System Information window under Help in Steam I am running Windows XP (64 bit).
Also wrong memory on my GTX 1080 "Primary VRAM: 2047 MB"
We're rebels. We're misfits. But mostly, we're software liberators. And we're very, very good at what we do. We have to be. Lots of developers work with open source, but only a tiny fraction of those are good enough to get software that was designed for one platform to work on another one. We invented CrossOver software - a unique approach to cross-platform compatibility that does not require dual-boot or another OS license. We launched PortJump to help app and game developers broaden their market beyond Windows® users. And we launched ExecMode to help organizations solve really ugly technical challenges.