New default VB.NET project immediately gives an error

Question

I just installed Mono version 2.10.8 and MonoDevelop 2.8.6.5 on a Mac. When I create a new project (File -> New solution -> VBNet -> ASP.NET -> Web Application) it gives me an error after creating: Error while trying to load the project '/Users/starquake/Development/Mono/HelloWorld/HelloWorld.vbproj': Project does not support framework '.NETFramework,Version=v4.0'

What am I doing wrong? Or how can I fix it?

Answer 1

I had this problem when creating new VB Projects, I changed the file format to use when creating new projects to MSBuild (Visual Studio 2008) instead of the default MSBuild (Visual Studio 2010) From Preferences > Load/Save

Answer 2

Using a text editor, change your *.vbproj file to add the following line:

    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>

to the first PropertyGroup, e.g.

<?xml version="1.0" encoding="utf-8"?>
<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    ...
    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
  </PropertyGroup>
  ...
</Project>

Answer 3

I had the same problem in Linux, but it seems that the version that properly supports VB.Net (at least without causing errors) is MonoDevelop 3.0.4, & after a google search, I landed on a SourceForge.net page with the newer MonoDevelop 3.0.6 source code.

I downloaded it, Extracted it's contents, & did the following in a root terminal...

      cd /home/knoppix/Downloads/monodevelop-3.0.6
      ./configure --prefix=`pkg-config --variable=prefix mono`
      make
      make install

Then closed the terminal, & ran MonoDevelop again, & it was no longer the version I had before (MonoDevelop 3.0.3), was now MonoDevelop 3.0.6.

When I created a new VB.Net GTK# 2.0 project, the errors were still there, but then I right-clicked on the project in the solution explorer, & chose Options, then under Build, I selected General... the 4.0 profile was now there, & could be selected. After selecting it, & closing the dialog, all the errors vanished.

I then changed the default format of new projects to MSBuild (Visual Studio 2010) from Edit, Preferences... then in the pop up dialog under Preferences, Load/Save.

I am still confused as to how to create a form though. C# side of things can create it easily, but I don't see the option in the VB side. I might have to install some other things to enable it, or something.

Answer 4

The VB.NET addin in MonoDevelop doesn't support the .NET 4.0 framework. I'm surprised it let you create an invalid project - that seems like a bug. Please file a report at http://bugzilla.xamarin.com.