I just installed a new clean local commerce manager on IIS 7.5
I added a new long html string metafield to the default catalog entry.
When I create a new product the cute editor cannot find dialog.css.
It reports 500-error on /Apps/Core/Controls/Editors/CuteEditor/Dialogs/Load.ashx?type=themecss&file=dialog.css&theme=Office2003_BlueTheme
The editor is pretty much useless as the tools are rended without css.
The configuration files for cute editor located under the shared folder of your commerce manager.
For example: C:\EPiServer\eCommerceFramework\5.2\CommerceManager\Shared\Apps\Core\Controls\Editors\CuteEditor.
Which browser that you met the error?