“调用的目标发生了异常”问题

首先原谅我将该问题放在首页，情况紧急，实在是没办法了，请各位帮忙！

我用下面语句来创建类型的一个实例：
ClassA Obj = (ClassA)Activator.CreateInstance(tasktype);
其中tasktype是Type类型

在执行上述语句时抛出异常：
Exception has been thrown by the target of an invocation.. （调用的目标发生了异常）

我在本地是好的，但在服务器上却抛出该异常。

服务器环境：
windows 2003 操作系统
.net FrameWork 2.0 + sp1补丁

请问这会是什么原因导致，该问题已经困扰我很长时间了。

 

以下是服务器“事件查看器”中日志信息：异常的Source、Message、StackTrace：
Source：mscorlib,
Message:Exception has been thrown by the target of an invocation.,
StackTrace: at System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandle& ctor, Boolean& bNeedSecurityCheck)
at System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean fillCache)
at System.RuntimeType.CreateInstanceImpl(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean fillCache)
at System.Activator.CreateInstance(Type type, Boolean nonPublic)
at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at System.Reflection.Assembly.CreateInstance(String typeName, Boolean ignoreCase, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at TaskScheduler.TTaskManager.PrepareTaskQueue() in c:\TaskScheduler\TaskManager.cs:line 94
at TaskScheduler.TTaskManager..ctor() in c:TaskScheduler\TaskManager.cs:line 64
at TaskScheduler.TTaskScheduler.RunTasks(Object sender) in c:\TaskScheduler\TaskScheduler.cs:line 58.