Fix crash when no display bindings are available.

src/Main/Base/Project/Workbench/DisplayBinding/IDisplayBinding.cs

@@ -50,7 +50,10 @@ namespace ICSharpCode.SharpDevelop.Workbench
 		/// </remarks>
 		/// <returns>
 		/// A newly created IViewContent object.
+		/// May return null if the view content could not be created.
 		/// </returns>
+		/// <exception cref="IOException">Error loading the file</exception>
+		/// <exception cref="FormatException">Error loading the file (invalid file format)</exception>
 		IViewContent CreateContentForFile(OpenedFile file);
 	}
 }

src/Main/SharpDevelop/Project/ProjectService.cs

@@ -36,7 +36,7 @@ namespace ICSharpCode.SharpDevelop.Project
 		{
 			allSolutions = new NullSafeSimpleModelCollection<ISolution>();
 			allProjects = allSolutions.SelectMany(s => s.Projects);
-			projectBindings = SD.AddInTree.BuildItems<ProjectBindingDescriptor>("/SharpDevelop/Workbench/ProjectBindings", null);
+			projectBindings = SD.AddInTree.BuildItems<ProjectBindingDescriptor>("/SharpDevelop/Workbench/ProjectBindings", null, false);
 			targetFrameworks = SD.AddInTree.BuildItems<TargetFramework>("/SharpDevelop/TargetFrameworks", null);
 			
 			SD.GetFutureService<IWorkbench>().ContinueWith(t => t.Result.ActiveViewContentChanged += ActiveViewContentChanged).FireAndForget();

src/Main/SharpDevelop/Workbench/DisplayBinding/AutoDetectDisplayBinding.cs

@@ -68,7 +68,7 @@ namespace ICSharpCode.SharpDevelop.Workbench
 			}
 			
 			if (bestMatch == null)
-				throw new InvalidOperationException();
+				return null;
 			
 			return bestMatch.Binding.CreateContentForFile(file);
 		}