Hello.
Does it mean this page is outside of Kentico
CMS project? As you mentioned two projects – one Kentico CMS and one custom. Anyway, if you are able to drag and drop given control onto your page, it probably mean that you have required dll registered properly and the problem is probably in properties you used… Could you please double-check that all required properties, like path, classname and transformation are filled properly? If so think so and still does not work, could you please post whole code here, so I can check it? Thank you.
Best Regards,
Radek Macalik