Converting VS2012 Solution to VS2010

I'm working in VB project with VS 2012 and after finish I try to add setup project.

I didn't find it (because the Setup Project was discontinued after VS2010) so I switched to VS2010 but the problem is the project wont open and I get this message:

> The selected file is a solution file but was created by a newer > version of this application and cannot be opened.

I tried this article : http://www.codeproject.com/Tips/80953/Converting-VS2010-Solution-to-VS2008 and tried to convert from 2012 to 2010 but same message appears.

I also faced the similar problem. I googled but couldn't find the solution. So I tried on my own and here is my solution.

Open you solution file in notepad. Make 2 changes

1. Replace "Format Version 12.00" with "Format Version 11.00" (without quotes.)
2. Replace "# Visual Studio 2012" with "# Visual Studio 2010" (without quotes.)

Hope this helps u as well..........

Just to elaborate on Bhavin's excellent answer - editing the solution file works but you may still get the incompatible error (as David reported) if you had .NET 4.5 selected as the default .NET version in your VS2012 project and your VS2010 enviroment doesn't support that.

To quickly fix that, open the VS2012 .csproj file in a text editor and change the TargetFrameworkVersion down to 4.0 (from 4.5). VS2010 will then happily load the "edited" solution and projects.

You'll also have to edit an app.config files that have references to .NET 4.5 in a similar way to allow them to run on a .NET 4.0 environment.

I had a similar problem and none of the solutions above worked, so I went with an old standby that always works:

1. Rename the folder containing the project
2. Make a brand new project with the same name with 2010
3. Diff the two folders and->
4. Copy all source files directly
5. Ignore bin/debug/release etc
6. Diff the .csproj and copy over all lines that are relevant.
7. If the .sln file only has one project, ignore it. If it's complex, then diff it as well.

That almost always works if you've spent 10 minutes at it and can't get it.

Note that for similar problems with older versions (2008, 2005) you can usually get away with just changing the version in the .csproj and either changing the version in the .sln or discarding it, but this doesn't seem to work for 2013.

the simplest solution is.....open your website in vs2013 and go to Debug->WebsiteProperties (last option) a new window will open..

in this window go to "Build" option and change .net framework version from 4.5 to 4.0.....then select ok. [note: this step will only work if your project does not have dependencies with vs2013...]

Now open your website in vs2010

Solution of VS2010 is supported by VS2012. Solution of VS2012 isn't supported by VS2010 --> one-way upgrade only. VS2012 doesn't support setup projects. Find here more about VS2010/VS2012 compatibility: http://msdn.microsoft.com/en-us/library/hh266747(v=vs.110).aspx

Open the project file and not the solution. The project will be converted by the Wizard, and after converted, when you build the project, a new Solution will be generated as a VS2010 one.

Simple solution which worked for me.

1. Install Vim editor for windows.
2. Open VS 2012 project solution using Vim editor and modify the version targetting Visual studio solution 10.
3. Open solution with Visual studio 2010.. and continue with your work ;)