C# 2008 Express: Project type (.csproj) is not supported by this version of the application

Question

I've been trying to look through some projects on CodePlex to try to get a feel for how others design their applications. I've run into some trouble trying to open these projects in C# 2008 Express. When I open either the solution or csproj files, I'm confronted with this error message:

'Foo.csproj' cannot be opened because its project type (.csproj) is not supported by this version of the application.

To open it, please use a version that supports this type of project.

This doesn't happen when I open projects I created myself. The external projects are even auto-converted from 2005 when they're in that format, but choke when it tries to open the converted file.

Is this a limitation on the Express editions, or is there something I can do to fix this?

I tried searching with Google, but the results I found were less than helpful.

Thanks!

UPDATES:
@JaredPar asked for the specific project which I'm having difficulties opening.
The proverbial 'straw that broke the camels back' is called Continuum, but I've also encountered difficulties with other projects on CodePlex, and also with the Paint.NET source.

I've tried uninstalling and reinstalling, but the problem persists.

@brianpeiris requested the specs for my install:

Visual Studio
Microsoft Visual Studio 2008
Version 9.0.30729.1 SP
Microsoft .NET Framework
Version 3.5 SP1

Installed Edition: C# Express

Microsoft Visual C# 2008 91910-152-0000061-60196
Hotfix for Microsoft Visual C# 2008 Express Edition with SP1 - ENU (KB945282) KB945282
Hotfix for Microsoft Visual C# 2008 Express Edition with SP1 - ENU (KB946040) KB946040
Hotfix for Microsoft Visual C# 2008 Express Edition with SP1 - ENU (KB946308) KB946308
Hotfix for Microsoft Visual C# 2008 Express Edition with SP1 - ENU (KB947540) KB947540
Hotfix for Microsoft Visual C# 2008 Express Edition with SP1 - ENU (KB947789) KB947789

System
System:
Microsoft Windows XP
Professional
Version 2002
Service Pack 2

Computer
AMD Turion(tm) 64 X2 Mobile
Technology TL-50
1.60 GHz, 1.75 GB of RAM
Physical Address Extension

Also, I should note that I have tried reinstalling VS, which didn't work. I've also installed the Web Developer Express as well, and while I can open and run the project from there, C# continues to frustrate.

Answer 1

The Continuum project's codebase is not too large. Try creating a new project in Visual C# Express and import the code manually. You'll probably have to add some references as well before you can build sucessfully.

Edit:

I just did this with the Continuum project.

Here's my process:

• Download and extract Continuum-1.1.1-Source.zip
• Delete Continuum.sln and Continuum.csproj
• Create a new Windows Forms project in Visual C# Express called Continuum
• Delete the default Form1.cs and Program.cs files and all the files under the "Properties" folder
• Save the new project and solution inside the previously extracted "Continuum" folder
• Enable "Show All Files" in the Solution Explorer
• Include all files and folders except the "bin", "obj" and "CompliedBinary" folders
  • Don't forget to include all the files under the "Properties" folder
• Add a reference to ZedGraph.dll (found under the "zedgraph_dll_v5.1.5" folder)
• Build and enjoy

Further Edit:

Here's a Unix diff of the unedited Continuum sln and csproj files compared to the ones I create using the process mentioned above. (I've merged the file manually to pick out the real differences.) (Ignore the syntax highlighting.)

Continuum_original.csproj vs Continuum_new.csproj

6c6
    <ProductVersion>9.0.21022</ProductVersion>
---
    <ProductVersion>9.0.30729</ProductVersion>
8c8
    <ProjectGuid>{FD0F9C26-38BF-473F-8FD4-FDB1C7BEA600}</ProjectGuid>
---
    <ProjectGuid>{E3E4FFA5-0EC3-4F94-B842-33C7A49B7FF5}</ProjectGuid>
13c13
    <TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
---
    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
37a38,46
    <Reference Include="System.Core">
      <RequiredTargetFramework>3.5</RequiredTargetFramework>
    </Reference>
    <Reference Include="System.Xml.Linq">
      <RequiredTargetFramework>3.5</RequiredTargetFramework>
    </Reference>
    <Reference Include="System.Data.DataSetExtensions">
      <RequiredTargetFramework>3.5</RequiredTargetFramework>
    </Reference>
225c234
  <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
---
  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />

Continuum_original.sln vs Continuum_new.sln

3,4c3,4
# Visual Studio 2008
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Continuum", "Continuum.csproj", "{FD0F9C26-38BF-473F-8FD4-FDB1C7BEA600}"
---
# Visual C# Express 2008
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Continuum", "Continuum.csproj", "{E3E4FFA5-0EC3-4F94-B842-33C7A49B7FF5}"
12,15c12,15
        {FD0F9C26-38BF-473F-8FD4-FDB1C7BEA600}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
        {FD0F9C26-38BF-473F-8FD4-FDB1C7BEA600}.Debug|Any CPU.Build.0 = Debug|Any CPU
        {FD0F9C26-38BF-473F-8FD4-FDB1C7BEA600}.Release|Any CPU.ActiveCfg = Release|Any CPU
        {FD0F9C26-38BF-473F-8FD4-FDB1C7BEA600}.Release|Any CPU.Build.0 = Release|Any CPU
---
        {E3E4FFA5-0EC3-4F94-B842-33C7A49B7FF5}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
        {E3E4FFA5-0EC3-4F94-B842-33C7A49B7FF5}.Debug|Any CPU.Build.0 = Debug|Any CPU
        {E3E4FFA5-0EC3-4F94-B842-33C7A49B7FF5}.Release|Any CPU.ActiveCfg = Release|Any CPU
        {E3E4FFA5-0EC3-4F94-B842-33C7A49B7FF5}.Release|Any CPU.Build.0 = Release|Any CPU

You'll notice that the files aren't significantly different and, as noted in the comments for this answer, I can actually open, compile and run the unedited Continuum 1.1.1 project! It appears the problem might be with the questioner's particular setup.

Here are my software and operating system version information:

Microsoft Visual Studio 2008 Version 9.0.30729.1 SP Microsoft .NET Framework Version 3.5 SP1

Installed Edition: C# Express

Microsoft Visual C# 2008
91910-152-0000061-60588 Microsoft Visual C# 2008

Hotfix for Microsoft Visual C# 2008 Express Edition with SP1 - ENU (KB945282) KB945282 For more information, visit http://support.microsoft.com/kb/945282.

Hotfix for Microsoft Visual C# 2008 Express Edition with SP1 - ENU (KB946040) KB946040 For more information, visit http://support.microsoft.com/kb/946040.

Hotfix for Microsoft Visual C# 2008 Express Edition with SP1 - ENU (KB946308) KB946308 For more information, visit http://support.microsoft.com/kb/946308.

Hotfix for Microsoft Visual C# 2008 Express Edition with SP1 - ENU (KB947540) KB947540 For more information, visit http://support.microsoft.com/kb/947540.

Hotfix for Microsoft Visual C# 2008 Express Edition with SP1 - ENU (KB947789) KB947789 For more information, visit http://support.microsoft.com/kb/947789.

OS Name Microsoft Windows Vista Version 6.0.6001 Service Pack 1 Build 6001

Answer 2

Try opening your .csproj -file with a text-editor and remove the ProjectType element that has a GUID - its usually the first entry under the first PropertyGroup.

Source