Me too. I'm using Microsoft Expression Web version 4. You?

I found what caused the errors on the DotNetNuke controls.

The DotNetNuke controls are registered on the top of the (ascx) page with something like:

"~" refers to the root of your website. (In my local installation case, it refers to "D:\DotNetNuke\".) So if you want to edit your skins in Microsoft Expression Web (4) use Open Site (Ctrl+Shift+O) on the root of your DotNetNuke installation. (I previously copied my skins to another directory (to be able to edit them without changing the original skin) and opened that directory. A beginners mistake.)

I must admit that I'm stil no fan of Microsoft Expression Web. It doesn't show me my website as my webbrowser does and if I want to change things (with as clean and maintainable code as possible) I still need to go to the underlying css. In my mind I can just as easily edit the css in my local(host) install and look at the changes in my browser. But being a beginner in Microsoft Expression Web I might overlook some functionality. If you want to convince me otherwise, feel free to do so. Thx.