I moved to a new server and all went well.  Then did an upgrade that had numerous errors because I didn't know you had to unzip all of the folders within folders.  So I tried to undo the upgrade with my backup copies and that failed, then ended up just deleting all files and website and starting over. But I keep getting this error message even though all of the files are from weeks before I tried the move to a new server and the separate sql database was restored to a copy from weeks ago. Any help is greatly appreciated.  I run IIS7.5 with .net 4.5 and a separate sql server database.

Collection cannot be null.
Parameter name: c

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: Collection cannot be null.
Parameter name: c

Source Error:

[ArgumentNullException: Collection cannot be null.
Parameter name: c]
   System.Collections.ArrayList..ctor(ICollection c) +10647211
   DotNetNuke.Entities.Portals.PortalController.GetPortals() +180
   DotNetNuke.Common.Initialize.CacheMappedDirectory() +36
   DotNetNuke.Common.Initialize.InitializeApp(HttpApplication app, Boolean& initialized) +324
   DotNetNuke.Common.Initialize.Init(HttpApplication app) +191
   DotNetNuke.HttpModules.RequestFilter.RequestFilterModule.FilterRequest(Object sender, EventArgs e) +229
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +136
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +69

Last Friday, I moved the file folder to the new server.  Setup the new site in IIS, added the apppool process to the folder and ran the site in chrome.  It worked perfectly.  So then I did the upgrade to 7.03 and received numerous errors that I discovered later were because I didn’t unzip all of the zipped folders before I ran the upgrade process.  So I restored the whole folder from back up after deleting the website and the folder, then rebuilt the website and ran it and got the error message below. So, that’s when I started asking for help from you.

Our DB Admin restored the database to a copy from the week before and I deleted everything off the new serve, rebooted and started over with clean copies of the files and the database this morning.  And I still get this error message.  There is no reason why I am still getting this message with all clean files and database. 

I am running server 2008, IIS 7.5, DotNet 4.5 is installed but the apppool processes are running under version 4.0.  And SQL stand alone, not sure what version.