Ok, So I've racked my head on this for hours... and I cannot find a solution.

I have a relatively old install that has moved up over the past 1.5 years through all the upgrades.  Now, when I try to upgrade from 4.5 to 4.7 (or even 4.6) I run into the null set refference issue in DotNetNuke.Provider.DNNProvider.dll

I've made sure that I adequately upgrade my web.config (it allows me to upgrade from 4.4 to 4.5 but no further)

I have attempted what others suggest and deleted some of my old SQLDataProvider.dll's

At this point I am resigned to believe that we will forever be stuck with 4.5.  Please help. 

Any recomendations of someone who I could empoy to solve this issue?

Thank you!

Here is the error as requested.

Value cannot be null.
Parameter name: type

Line 80: 
Line 81:             'Determine the Upgrade status and redirect to Install.aspx
Line 82:             Select Case GetUpgradeStatus()
Line 83:                 Case Globals.UpgradeStatus.Install
Line 84:                     If AutoUpgrade Then

[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.Data.DataProvider.CreateProvider() +47
   DotNetNuke.Data.DataProvider..cctor() +13

[TypeInitializationException: The type initializer for 'DotNetNuke.Data.DataProvider' threw an exception.]
   DotNetNuke.Common.Globals.GetUpgradeStatus() +67
   DotNetNuke.Common.Global.CheckVersion() in D:\SkyeWeb\Website\App_Code\Global.asax.vb:82
   DotNetNuke.Common.Global.Application_Start(Object Sender, EventArgs E) in D:\SkyeWeb\Website\App_Code\Global.asax.vb:310

Also: here is my connection string (I am using SQL Server 2005 express):

    <!-- Connection String for SQL Server 2005 Express -->
            <add name="SiteSqlServer" connectionString="Data Source=XXXX\U15221866;Initial Catalog=YYYY;User Id=YYYYY;Password=ZZZZZ" providerName="System.Data.SqlClient" />
    <!-- Connection String for SQL Server 2000/2005
    <add
      name="SiteSqlServer"
      connectionString="Server=(local);Database=DotNetNuke;uid=;pwd=;"
      providerName="System.Data.SqlClient" />
   -->
    </connectionStrings>
    <appSettings>
    <!-- Connection String for SQL Server 2005 Express - kept for backwards compatability - legacy modules   -->
    <add key="SiteSqlServer" value="Data Source=XXXX\U15221866;Initial Catalog=YYYY;User Id=YYYYY;Password=ZZZZZ" />
    <!-- Connection String for SQL Server 2000/2005 - kept for backwards compatability - legacy modules
    <add key="SiteSqlServer" value="Server=(local);Database=DotNetNuke;uid=;pwd=;"/>
    -->

----

as you can see, I removed the ";" at the end of the connection strings and still no love.

I believe it has something to do with old/obsolete dlls, but I have tried to eliminate one-by-one in the bin and no love.

Thanks,

Thanks for the pointers, however none worked as of yet:

1. The version table shows that it never got upgraded from 4.5.5 (the last entry). 

2. web.config - permissions are already set for Network Service.  (besides, wouldn't this have already come up in previous upgrades?)

3. Connecting to the Database - this is the exact connection string used in past versions for flawless execution (if i include the ";" at the end of the connection string, I get a different 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.Data.DataProvider.CreateProvider() +47
   DotNetNuke.Data.DataProvider..cctor() +13

[TypeInitializationException: The type initializer for 'DotNetNuke.Data.DataProvider' threw an exception.]
   DotNetNuke.Entities.Portals.PortalAliasController.GetPortalAliasByPortalID(Int32 PortalID) +38
   DotNetNuke.Entities.Portals.PortalSettings.GetPortalAliasLookup() +74
   DotNetNuke.Entities.Portals.PortalSettings.GetPortalAliasInfo(String PortalAlias) +14
   DotNetNuke.HttpModules.UrlRewriteModule.RewriteUrl(HttpApplication app) +3527
   DotNetNuke.HttpModules.UrlRewriteModule.OnBeginRequest(Object s, EventArgs e) +826
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +92
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +64

 Is this progress or just making it worse?

thanks,