Hello Albert,

In general, the Window containment functionality is not intended to work in combination with the modal option. This is the case, as the containment is supposed to constrain the Window in a certain bounds and this is not suitable for scenarios where there is a modal overlay on the page. We will update the documentation to outline this specific use case of the options.

Taking the above into consideration, I would suggest to use the containment with the modal option set to false. However, in case you would like to preserve the modal option and keep the current behavior, you could subscribe to the Window close event, query the document body for ".k-overlay" and if one is found - remove it. This will take care of the overlay issue for the specific Window implementation.

Regards,
Dimitar
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