If you install Azure SDK 1.4 and then your web roles say System.TypeLoadException for System.ServiceModel.Activation.HttpModule in ASP.NET 4

If you install Azure SDK 1.4 and then your web roles say System.TypeLoadException for System.ServiceModel.Activation.HttpModule in ASP.NET 4, then follow this advice

http://blogs.iis.net/webtopics/archive/2010/04/28/system-typeloadexception-for-system-servicemodel-activation-httpmodule-in-asp-net-4.aspx

and run:

aspnet_regiis -iru

in a "run as admin" command prompt

An excellent walkthrough on how to get connectionstrings integrated into Azure roles

Excellent walkthrough - here

http://romikoderbynew.wordpress.com/2011/02/02/using-autofac-mvc3-sqlmembershipprovider-and-entity-framework-in-windows-azure-and-sql-azure/ 

The ViewData item that has the key 'XXX' is of type 'System.Int32' but must be of type 'IEnumerable'.

If you're using ASP.Net MVC and you get this message using a DropDownList...

... then check whether the IEnumerable you think you are passing in actually exists in your ViewBag/ViewData

If you're using EntityFramework and you see this error - 

A value shared across entities or associations is generated in more than one location.

Then what it means is: you've set up inheritance using multiple tables and you've left the key autogenerated in one of the derived types.