Hello,

I'm trying to install a package which has a few DocumentTypes, but every time I try to install it I get the the following error:

Object reference not set to an instance of an object. 
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.NullReferenceException: Object reference not set to an instance of an object.

Source Error: 

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.  

Stack Trace: 


[NullReferenceException: Object reference not set to an instance of an object.]
   umbraco.cms.businesslogic.packager.Installer.InstallBusinessLogic(Int32 packageId, String tempDir) +4488
   umbraco.presentation.developer.packages.Installer.processInstall(String currentStep) +282
   umbraco.presentation.developer.packages.Installer.Page_Load(Object sender, EventArgs e) +548
   System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
   System.Web.UI.Control.OnLoad(EventArgs e) +91
   umbraco.BasePages.BasePage.OnLoad(EventArgs e) +49
   System.Web.UI.Control.LoadRecursive() +74
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2207