So, this one is a real head-scratcher for me.
I created a custom registration page:
If I view that as an anonymous user (ie not logged in) the client-side scripting doesn't work. You can test this by clicking the 'Register' button with no information supplied. Instead of getting the 'please supply username' type messages, it will postback and show no error messages.
Now, if I instead view it at this Url:
Then it works OK -clicking on the 'register' button will show the client-side validation messages.
The further wrinkle is that if I am logged in as an Administrator, the /join Url works OK. It's only for anonymous users that the problem exists.
I can't recreate this problem in a standard 6.2.1 install.
The issue is that the client-side scripting libraries are never even requested - a Fiddlre trace shows that the /scriptResource.axd and a /Telerik.Web.UI.WebResource.axd?compress=1&_TSM_CombinedScripts_=%3b%3bTelerik.Web.UI... request is missing from the one that doesn't work.
But I don't understand - what would be the difference between specifying an individual module do in terms of getting the client-side scripting component to download.
I've burnt hours trying to figure this one out, so I'm ready for some new ideas to come in from left field.