Hi Daniel Schilling,
Actually this error may occur due to several reasons. One of them is if the connection to the database has been lost or if the DSW failed to load the model project (Installer problem).
So lets try the basic steps to use the DSW to make sure there is no problems with the installed DSW version:
1- Create a new Class library (.Net V4.0).
2- Add a domain model, set the connection string to the Northwind database.
3- Do not change the connection string name.
4- Select Tables only.
5- Add new Web application project (.Net V4.0).
6- Open the DSW.
If you are still not able to make it work, I think the problem was produced from the installer, so I would suggest you to reinstall the product (Please double check your GAC that there are no Telerik.OpenAccess assemblies left after you uninstall the product).
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items