问题
I am unable to open CSS files in Visual Studio 2010 after adding to a project.
It shows the following error:
The operation could not be completed.Unspecified error.
Even if I try to edit embedded CSS in a webpage directly, IntelliSense doesn't appear.
回答1:
I found the solution from here:
I was having the same issue and found that by going to the Tools -> Extension Manager -> Online Gallery and search for/install the "Web Standards Update for Microsoft Visual Studio 2010 sp1" I was able to open CSS files again.
And it worked for me.
回答2:
Probably it can happen after installing the Visual Studio LightSwitch beta
OR
Windows Azure tools installed
OR
SQL Server 2012 installed
Download this and install it if already installed then repair it and it'll fix the issue:
http://visualstudiogallery.msdn.microsoft.com/a15c3ce9-f58f-42b7-8668-53f6cdc2cd83
回答3:
This happened to me after installing Adobe Cloud production suite. Web Standards Update did the trick.
回答4:
There is dropdown box in the toolbar saying "XHTML 1.0 transition". Change it to HTML.
来源：https://stackoverflow.com/questions/6731470/css-file-not-opening-in-visual-studio-2010-sp1