I upgraded from 5.X (5.4 I think perhaps?) to 6.0.  I keep one website as a default instance without any clever modules, basically the default website.  I use this for administering other host portals with the thought that anything I do to mess things up with skins or whatever can't affect my master portal admin website.

I loaded the website and immediately got an error.  I took the default web.config from the 6.0 install (not upgrade) zipfile as a base, migrated my SQL login settings and GUID.  Tried again and the site loaded.  However, when I log in, I get:

An error has occurred.DotNetNuke.Services.Exceptions.PageLoadException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.UI.Containers.ActionButtonList.get_ModuleActions() at DotNetNuke.UI.Containers.ActionButtonList.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace ---

 I found that by copying one line from the navigation providers from my old web.config to my new one fixed the problem:

<add name="DDRMenuNavigationProvider" type="DotNetNuke.Web.DDRMenu.DDRMenuNavigationProvider, DotNetNuke.Web.DDRMenu" />

I did a full compare with my web.config and the 6.0 stock web.config usign Notepad++
Initially I let DNN upgrade do the merge, but since that didn't work at all, I started with the 6.0 stock web.config and manually merged my entries in there.  The DIFF didn't show many changes other than SQL login string, GUID, and the one provider I referenced above.  Other stuff was housekeeping such as install date, which I assume doesn't affect much.  I can post my entire web.config as it stands if that would be helpful.

Cheers,
Tim

> check your web.config is not set to true -if it is set it to false

no idea what you are asking me to do here?

> can you check that you are not using the whitespace remover (host->host settings, click advanced ensure whitespace filter is unchecked)

I looked and yes, it was already unchecked.

>can you check you do not have duplicate named skins in portals\_default\skins and one or more portals folders i.e. portals\_default\skins - if so please remove the duplicates

those two paths are the same, did you mean that?  I checked portals\_default\skins and there don't appear to be any duplicate names in there (I don't think Windoze would allow that anyway).  Everything looks fairly unique.