Lukas, entretanto esqueci disto.
Aqui tens um SLN para o Visual Studio "normal":
Código :Microsoft Visual Studio Solution File, Format Version 11.00
# Visual Studio 2010
Project("{F184B08F-C81C-45F6-A57F-5ABD9991F28F}") = "Canyon", "Canyon\Canyon\Canyon.vbproj", "{D275CDA3-3653-4B0B-AC1D-344E1A4159FC}"
EndProject
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "CanyonContent", "Canyon\CanyonContent\CanyonContent.contentproj", "{4BA70684-32FC-4038-9A06-F0FDA39E03AE}"
EndProject
Global
GlobalSection(SolutionConfigurationPlatforms) = preSolution
Debug|x86 = Debug|x86
Release|x86 = Release|x86
EndGlobalSection
GlobalSection(ProjectConfigurationPlatforms) = postSolution
{D275CDA3-3653-4B0B-AC1D-344E1A4159FC}.Debug|x86.ActiveCfg = Debug|x86
{D275CDA3-3653-4B0B-AC1D-344E1A4159FC}.Debug|x86.Build.0 = Debug|x86
{D275CDA3-3653-4B0B-AC1D-344E1A4159FC}.Release|x86.ActiveCfg = Release|x86
{D275CDA3-3653-4B0B-AC1D-344E1A4159FC}.Release|x86.Build.0 = Release|x86
{4BA70684-32FC-4038-9A06-F0FDA39E03AE}.Debug|x86.ActiveCfg = Debug|x86
{4BA70684-32FC-4038-9A06-F0FDA39E03AE}.Release|x86.ActiveCfg = Release|x86
EndGlobalSection
GlobalSection(SolutionProperties) = preSolution
HideSolutionNode = FALSE
EndGlobalSection
EndGlobal
Basta substituíres o conteúdo do teu Canyon.sln por esse acima.