Ajax Control toolkit - Element is not a known element

Hi,

I have installed the Ajax Control Toolkit on my pc in Visual Studio 2008.

If I use one of the controls on my aspx page in my website stored locally on my pc everything works fine.

If I use one of the controls on my aspx page in my website stored on a network drive I get the error

Element is not a known element and the control has a green zig-zag underline.

Is there something I need to install on the network server?

Is this a permission issue?

I already use script manager and update panel with no problem but can't seem to get this new Ajax Control Toolkit to work using a network drive

Any help would be greatly appreciated

Andy.