The Result List Designer is only available in the administration, if a result list has been assigned to a web instance.

You can get a list of available result lists in the DocuWare Administration under "File Cabinets" -> "Dialogs" --> "Result Views".
In the area "Publish to Web Instance" you have to assign the result to at least one Web Instance and can then click on the "OpenDesigner" button at the end of the line.Please do no tforget to pop up the are aso you can see the button.

At the registration on List Designer please note, that you login with a user account that has access to the appropriate result list.