Hello john mirzaei,
Thank you for getting back to us.
Can you tell us which version of Sitefinity are you using? Is it possible that you are using an older version of Sitefinity (for example Sitefinity 3.6 SP2), and you have downloaded the latest external templates archive. In the older versions of Sitefinity, the line that is giving you errors was:
'<%= Page.ResolveUrl("~/Sitefinity/UserControls/Dialogs/ImageEditorDialog.aspx") %>'
If you are using external templates for a different version of Sitefinity, you might get this kind of errors, because all external templates are made for a specific version. To solve this check your version of Sitefinity, as described in this article
. Then download the correct external templates.
The culture of the DateTime picker is changed by modifying the controls properties, by following this example
the Telerik team