Visual Studio 2012 Designer throws exception 0x80270257

TLDR; VS2012 throws an exception like below when trying to edit XAML in the Designer running VS2012 as a RemoteApp.

Right, I may be asking this in the wrong place, but I'm at my wits end with this. Basically what I'm trying to achieve is to run VS2012 on my Surface RT for quick edits of Windows Store apps. The way to do this is to run it as a RemoteApp which actually works great considering you can just hit F5 to build and launch for debug directly on the Surface, the problem is that the VS Designer bombs and throws the exception below.

For initial lab tests I was running VDI as a Session mode setup - i.e. VS2012 was running on WS2012, this gave the exact same exception as described herein. But after discussing it with some people way more into VDI than me we came to the conclusion that it was because it was running on WS2012 and not Windows 8. So I went ahead and changed things around running VDI in virtualization mode.

Said and done I spent a day installing and tailoring a Windows 8 Pro image with VS2012, various SDKs and whatnot. When it came to sysprepping this I ran into a different issue in that sysprep would bomb out with a "fatal error", after another day of trawling through the web and speaking to support it was decided this was because the pre-installed Windows Store apps had been updated. So another day gone reinstalling everything, this time sysprep worked fine and I was able to commission the virtual desktop, however when it came to publishing Visual Studio (among others) as a RemoteApp again I ran into issues. After another day and a half googling, binging, tweeting and finally calling support it transpired this was because only Windows 8 Enterprise edition could be used for RemoteApp publishing ... thanks MS, you couldn't have made this clear in your "best practices"? Anyway, spending another day reinstalling windows and all apps, SDKs and documentation. This time I am finally able to both sysprep, commission and publish RemoteApps. Yey, I'm a happy camper seeing as I should finally be able to do what I set out to do - quick XAML edits and debugging directly on my Surface RT.

Not so.. as the exception is, some five hundred reinstalls later still rearing it's ugly head. The "gurus" I initially spoke to are as stumped as me and can only offer that "it should work" and "it worked fine for the person I configured it for".

So, any ideas greatly appreciated here. While I can use the text editor to edit the XAML and Bob's my uncle in terms of quickfixes and debugging sessions I would much prefer to have it working properly and to be able to use the visual designer (or Blend - as the same exception is thrown there) for certain changes.

This is the actual exception; 2

I had the same problem and I just found a solution.

I had the Windows 'explorer' shell deactivated because I am using BBlean (an alternate shell for Windows, based on BlackBox). Apparently this was blocking the app manager. Disabling BBlean and starting Windows normally fixed the error.

So if you happen to be using a replacement shell, try disabling it.