Hi Viv,

See if http://www.code-magazine.com/article.aspx?quickid=0603031&page=1 can help.

>
>I need to access a couple of external assemblies for a SQLCLR assembly. AFAICS one way to do this is to:
>(a) Set the permission level to 'External' in the .NET project.
>(b) Grant the dbo of the relevant database 'External Access Assembly' permissions
>(c) Mark the relevant database as 'Trustworthy'
>
>I've done all three but still get a permissions error when the CLR tries to access the System.Runtime.Serialization.dll module.
>
>Can anyone suggest what else might be required?
>Regards,
>Viv