Hi Donald,

Because DNN uses its own localization system, it requires the ASP.NET localization system be disabled.  This is accomplished by disabling build services for files with extensions in the set {".resx", ".resources"}.

Your error indicates that ASP.NET localization has not been properly disabled.  You will need to figure out why.

Some possibilities:

1. Missing web.config.  Are you using the upgrade package for a new installation? 

2. Are the build directives for resources missing from your web.config?  Check configuration/system.web/compilation/buildProviders for the following entries:

<buildProviders>

<remove extension=".resx" />

<remove extension=".resources" />

</buildProviders>

3. Improper IIS configuration.  Do you have an overriding application configured below your installation directory at the IIS level?  This is perhaps the least likely of the above options.

Hope this gets you started!

Brandon