构建源代码时umbraco cms错误

Question

我正在尝试在Visual Studio 2012中构建Umbraco cms源代码，并在PluginManager.cs下面的行中继续收到以下错误

try
            {
               **var typeInstance = (T)Activator.CreateInstance(t);**
                instances.Add(typeInstance);
            }
            catch (Exception ex)
            {

                LogHelper.Error<PluginManager>(String.Format("Error creating type {0}", t.FullName), ex);

                if (throwException)
                {
                    throw ex;
                }
            }

错误指向此行

**var typeInstance = (T)Activator.CreateInstance(t);**

并说'对象引用未设置为对象的实例。'