Value cannot be null. Parameter name: value in IIS 7.5

I am migrating a website on IIS 7.5 from IIS 6.0. In IIS 6.0 i was using UrlRewriting and code is working fine. I have configured the website through Classic Asp.net app pool. I have also updated the rewrite rules in the web config as per IIS 7. I am getting this error when i want to open a page in the browser.

Server Error in '/' Application.

Value cannot be null.

Parameter name: value

Stack Trace: [ArgumentNullException: Value cannot be null. Parameter name: value] System.Web.Caching.CacheEntry..ctor(String key, Object value, CacheDependency dependency, CacheItemRemovedCallback onRemovedHandler, DateTime utcAbsoluteExpiration, TimeSpan slidingExpiration, CacheItemPriority priority, Boolean isPublic) +11691362 System.Web.Caching.CacheInternal.DoInsert(Boolean isPublic, String key, Object value, CacheDependency dependencies, DateTime utcAbsoluteExpiration, TimeSpan slidingExpiration, CacheItemPriority priority, CacheItemRemovedCallback onRemoveCallback, Boolean replace) +144 System.Web.Caching.Cache.Insert(String key, Object value) +110 URLRewriter.Config.RewriterConfiguration.GetConfig() +247 URLRewriter.ModuleRewriter.Rewrite(String requestedPath, HttpApplication app) +178 URLRewriter.BaseModuleRewriter.BaseModuleRewriter_AuthorizeRequest(Object sender, EventArgs e) +158 System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +80 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +270

Any ideas to resolve this issue or Why the issue is occuring?

Thanks In Advance