The visual studio template for Lemoon 4.3 is targeted for Visual Studio 2010. The following workaround should make it possible to use with Visual Studio 2008:
After you get the error above you should edit the .csproj- file in your new project and modify it like this:
Change:
<Import Project="$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v10.0\WebApplications\Microsoft.WebApplication.targets" />
To:
<Import Project="$(MSBuildExtensionsPath)\Microsoft\VisualStudio\v9.0\WebApplications\Microsoft.WebApplication.targets" />
It should now be possible to load the project in Visual Studio 2008.