Error 500 when using advanced fileupload (drag and drop)

If you are using Themes in your EPiServer CMS templates, chanses are good you cannot use the drag and drop functionallity in EPiServer File Manager.

Lets say you create a theme called myTheme. Then you’ll probably add this to web.config’s pages-element instead of add it to all templates.

<pages theme=”myTheme”>

After adding this to web.config, drag and drop stop working. You can easily solve this by adding a pages-element to your UI-location:

<location path=”UI”>
    <system.web>
        <pages theme=”” />

Now you can start dragging thoose files :)