On design screen component won't show on execution

Hello,

Please, can someone tell me why the dropdown isn't generated? I am putting this control on the design screen of Radzen studio. But it wont show when the application is executed.

Il also tried to replace it by another control (DatePicker) but still the same result
Regards!

It will be hard to receive any help if you don't post at least a screenshot, some more info about any settings, any errors or whatever more info.

Sorry ... the file was at an exception "not to be generated" ... Will delete the post