My 4.8 upgrade failed with the following error message.   I now can't get access to my site.   Any suggestions?

Server Error in '/' Application.

---

Value cannot be null.
Parameter name: type

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.ArgumentNullException: Value cannot be null.
Parameter name: type

Source Error:

[ArgumentNullException: Value cannot be null.
Parameter name: type]
   System.Activator.CreateInstance(Type type, Boolean nonPublic) +2768503
   DotNetNuke.Framework.Reflection.CreateObject(String ObjectProviderType, String ObjectProviderName, String ObjectNamespace, String ObjectAssemblyName, Boolean UseCache) +582
   DotNetNuke.Framework.Reflection.CreateObject(String ObjectProviderType, String ObjectNamespace, String ObjectAssemblyName) +17
   DotNetNuke.Security.Membership.Data.DataProvider.CreateProvider() +38
   DotNetNuke.Security.Membership.Data.DataProvider..cctor() +13

[TypeInitializationException: The type initializer for 'DotNetNuke.Security.Membership.Data.DataProvider' threw an exception.]
   DotNetNuke.Security.Membership.Data.DataProvider.Instance() +0
   DotNetNuke.Security.Membership.AspNetMembershipProvider..cctor() +5

[TypeInitializationException: The type initializer for 'DotNetNuke.Security.Membership.AspNetMembershipProvider' threw an exception.]

[TargetInvocationException: Exception has been thrown by the target of an invocation.]
   System.RuntimeTypeHandle.CreateInstance(RuntimeType type, Boolean publicOnly, Boolean noCheck, Boolean& canBeCached, RuntimeMethodHandle& ctor, Boolean& bNeedSecurityCheck) +0
   System.RuntimeType.CreateInstanceSlow(Boolean publicOnly, Boolean fillCache) +103
   System.RuntimeType.CreateInstanceImpl(Boolean publicOnly, Boolean skipVisibilityChecks, Boolean fillCache) +261
   System.Activator.CreateInstance(Type type, Boolean nonPublic) +66
   DotNetNuke.Framework.Reflection.CreateObject(String ObjectProviderType, String ObjectProviderName, String ObjectNamespace, String ObjectAssemblyName, Boolean UseCache) +582
   DotNetNuke.Security.Membership.MembershipProvider.CreateProvider() +38
   DotNetNuke.Security.Membership.MembershipProvider..cctor() +13

[TypeInitializationException: The type initializer for 'DotNetNuke.Security.Membership.MembershipProvider' threw an exception.]
   DotNetNuke.Security.Membership.MembershipProvider.Instance() +0
   DotNetNuke.Entities.Users.UserController..cctor() +5

[TypeInitializationException: The type initializer for 'DotNetNuke.Entities.Users.UserController' threw an exception.]
   DotNetNuke.Entities.Users.UserController.GetUserCountByPortal(Int32 portalId) +0
   DotNetNuke.Entities.Portals.PortalInfo.get_Users() +17
   DotNetNuke.Entities.Portals.PortalSettings.GetPortalSettings(Int32 TabId, PortalAliasInfo objPortalAliasInfo) +1302
   DotNetNuke.Entities.Portals.PortalSettings..ctor(Int32 tabId, PortalAliasInfo objPortalAliasInfo) +82
   DotNetNuke.HttpModules.UrlRewriteModule.OnBeginRequest(Object s, EventArgs e) +3306
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +92
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +64

Robert,

I hit the exact same error upgrading a live (shared hosting) DNN 4.6.2 site to DNN 4.8.0 (install version)  this afternoon - my first upgrade or install failure since starting with DNN 3 years ago - even after having successfully upgraded several test installs to 4.8.0.  When first hitting Install.aspx following uploading the new version's files, the upgrade seemed to proceed properly through running the sql scripts for 4.7.0 and 4.8.0 then abruptly stopped with an Application Error. Note that the Application Errors that we received relating to a type initializer exception due to a null value in the parameter 'type' are quite different than the one that the other poster mentioned involving problems with the Active Directory provider. My site which failed to upgrade does not use AD.

Although I could have rolled the site back thanks to complete backup of files and database I decided to try to check/try a few remedies first. After finding no problems with the modifications I had made to the new 4.8.0 web.config file and verifying that all of the new files had been properly uploaded via FTP and noting that the database had indeed been updated to 4.8.0 (as seen in the DNN Version table entry, I noticed that there were 16 dll files from prior versions still residing in the \bin folder.  With the 4.7 upgrade, there was a major shift in the way in which the HttpModules and Providers were compiled, no longer requiring separate dll's for each HttpModule nor for each provider.  I then deleted the following files from the \bin folder of the live site:

DotNetNuke.Authentication.ADSI.dll
DotNetNuke.Authentication.ADSIProvider.dll
DotNetNuke.DNNScheduler.SqlDataProvider.dll
DotNetNuke.HttpModules.Authentication.dll
DotNetNuke.HttpModules.Compression.dll
DotNetNuke.HttpModules.DNNMembership.dll
DotNetNuke.HttpModules.Exception.dll
DotNetNuke.HttpModules.Personalization.dll
DotNetNuke.HttpModules.UrlRewrite.dll
DotNetNuke.HttpModules.UsersOnline.dll
DotNetNuke.Provider.DBLoggingProvider.SqlDataProvider.dll
DotNetNuke.Provider.Membership.SqlDataProvider.dll
DotNetNuke.Provider.SQLMembershipProvider.dll
DotNetNuke.Provider.SQLProfileProvider.dll
DotNetNuke.Provider.SQLRoleProvider.dll

After restarting the site in my hosting provider's control panel, the site reappeared with no apparent errors when I revisited it.

I can think of two reasons for the failure with the first being the most likely at the root of the problem:

1. When I unzipped the 4.8.0 Install I did so into the same folder which I had used for several prior installs, with the result that the now obsolete dll files were still located in the \bin folder at the time they were FTP'd up to the live site. I don't know if some or all of these obsolete files had been automatically removed (thanks to the presence of the 04.06.00.txt file in the \Portals\_default folder) when I had updated the site from 4.5.5 to 4.6.2 a while back and I simply restored them at the time or this upgrade or if they were already there.

2. The live site had gone down due to server problems a couple of times in the hour preceeding the start of this upgrade. Perhaps it went down during this upgrade resulting in failure of the upgrade process to complete including the automatic removal of the obsolete dll's prior to restarting the site.

At any rate, I learned one good lesson that had apparently not cought up with me in many prior upgrades of this and other sites - DO NOT unzip a new version's install into a folder used previously to upload files to the host server. Use a clean folder or at least delete all files from the \bin folder first!  Hope this helps you and others with the same problem!

** POP **

Can anyone please tell me how I should declare the modules above in my web.config file for DNN v4.8.1.

Do I use the <system.webServer> declarations or the <httpModules> definition or both?