I would like to ask you for your help.
I added 1 webpage widget (duration 900sec) to one of the regions (containing many widgets) and saved.When I try to preview the layout, new webpage is not there.I tried to remove the webpage and put it back and nothing changed.Since then it is impossible to publish the layout. It says : This layout is invalid and should not be scheduled.
I do not have any extra empty region in the layout. Webpage widget contains link.