I have recently tried to change the forms authentication tag on my
web.config and i noticed that all the radmenus now have disappeared, i then
change back the web config and remove the domain attribute and they
work now normal.
Do anyone knows why this happens?


    <authentication mode="Forms">
      <forms name="appname" loginUrl="login.aspx" timeout="480" domain="domain.com" />
    </authentication>

Hello,

Several possible reason for the issue are described in this help topic- and  more specific in adding a <location> section to the application configuration file to allow access to Telerik.Web.UI.WebResource.axd to all users. 

Hope this will help you solve the issue.

Regards,
Plamen
Telerik