In 2006 we installed umbraco 3 and used the blog. I recall with no documentation it was a nightmare and now I'm having to upgrade the website and the blog to v4.7. I've installed to 4 then 4.5.2 which is where I am now. With some help from google I was able to get this far, it wasn't plain sailing to do the upgrade. The biggest issue I have is that the upgrade to version 4 broke the Blog in the back end, that is to say when I click on a blog post I get the yellow screen of death on the right handle content edit area. I thought upgrading to 4.5.2 might resolve it but it's still there. So I'm now thinking upgrading to blog4umbraco 2 might resolve the issue but when I try to install the packaged I'm getting the following error:

Could not find datatype with id 71b8ad1a-8dc2-425c-b6b8-faa158075e63.

A topic with the same issue suggested doing a sql update:

http://blog4umbraco.codeplex.com/workitem/5399

I ran that but it would appear the datatype with id isn't there in the first place to update so that 'solution' isn't working for me.

Here's the full stack trace I'm seeing:

Event code: 3005 
Event message: An unhandled exception has occurred. 
Event time: 7/06/2011 10:10:50 a.m. 
Event time (UTC): 6/06/2011 10:10:50 p.m. 
Event ID: 6ff62f369a2f449f8e5a37a6336b8903 
Event sequence: 218 
Event occurrence: 6 
Event detail code: 0 
 
Application information: 
    Application domain: /LM/W3SVC/3/ROOT-1-129518702959923444 
    Trust level: Full 
    Application Virtual Path: / 
    Application Path: E:\Work\Umbraco\ 
    Machine name: FFAD965ZT1S 
 
Process information: 
    Process ID: 2644 
    Process name: aspnet_wp.exe 
    Account name: FFAD965ZT1S\ASPNET 
 
Exception information: 
    Exception type: Exception 
    Exception message: Could not find datatype with id 71b8ad1a-8dc2-425c-b6b8-faa158075e63.
   at umbraco.cms.businesslogic.packager.Installer.ImportDocumentType(XmlNode n, User u, Boolean ImportStructure)
   at umbraco.cms.businesslogic.packager.Installer.InstallBusinessLogic(Int32 packageId, String tempDir)
   at umbraco.presentation.developer.packages.Installer.processInstall(String currentStep)
   at umbraco.presentation.developer.packages.Installer.Page_Load(Object sender, EventArgs e)
   at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e)
   at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e)
   at System.Web.UI.Control.OnLoad(EventArgs e)
   at umbraco.BasePages.BasePage.OnLoad(EventArgs e)
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

 
 
Request information: 
    Request URL: http://umbraco/umbraco/developer/packages/installer.aspx?installing=businesslogic&dir=E:\Work\Umbraco\data\1c791343-f718-4c43-b718-aad03a3a1a2f&pId=1 
    Request path: /umbraco/developer/packages/installer.aspx 
    User host address: 127.0.0.1 
    User:  
    Is authenticated: False 
    Authentication Type:  
    Thread account name: FFAD965ZT1S\ASPNET 
 
Thread information: 
    Thread ID: 13 
    Thread account name: FFAD965ZT1S\ASPNET 
    Is impersonating: False 
    Stack trace:    at umbraco.cms.businesslogic.packager.Installer.ImportDocumentType(XmlNode n, User u, Boolean ImportStructure)
   at umbraco.cms.businesslogic.packager.Installer.InstallBusinessLogic(Int32 packageId, String tempDir)
   at umbraco.presentation.developer.packages.Installer.processInstall(String currentStep)
   at umbraco.presentation.developer.packages.Installer.Page_Load(Object sender, EventArgs e)
   at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e)
   at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e)
   at System.Web.UI.Control.OnLoad(EventArgs e)
   at umbraco.BasePages.BasePage.OnLoad(EventArgs e)
   at System.Web.UI.Control.LoadRecursive()
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
 
 
Custom event details: 

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

I've been fighting with this on and off for about 3 days now and I'm feeling very frustrated with Umbraco all over again, the woes of 2006 are vividly coming back. Looking for help on the site I'm finding bad links all over the place which doesn't help at all. If there's one thing worse than no documentation it's saying there is documentation or tutorials and then they go to nowhere. I was hoping v4 was going to be a little smoother to work with, please can someone help me out. I'm on a very tight deadline and if I tell the boss Umbraco is causing me issues again he's going to be a tad tempersome.