Bad IL format.

请教：如果出现以下错误时应该怎么办？谢谢！

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.BadImageFormatException: Bad IL format.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:


[BadImageFormatException: Bad IL format.]
Caicai.Framework.Common.UrlRewrite.Init(HttpApplication objApp) +0
System.Web.HttpApplication.InitModulesCommon() +80
System.Web.HttpApplication.InitModules() +43
System.Web.HttpApplication.InitInternal(HttpContext context, HttpApplicationState state, MethodInfo[] handlers) +828
System.Web.HttpApplicationFactory.GetNormalApplicationInstance(HttpContext context) +304
System.Web.HttpApplicationFactory.GetApplicationInstance(HttpContext context) +107
System.Web.HttpRuntime.ProcessRequestInternal(HttpWorkerRequest wr) +327




--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1

.Net4.0不能向下兼容，先变更为.Net2.0网站，软件需要.Net2.0框架的支持。