That won't work.
YouTube, just like a number of other widget providers changed the way they insert their embeddable content so it means that in order to see the video or whatever content it is, you need to be viewing your page online after you have published it.
In version 9 work was done within the program to address this as more and more widget providers are making similar changes so there is a solution built into the program which means that when you insert these widgets they will just immediately work.
If you're seeing 'Navigation to the page was cancelled' then it's almost certainly going to work as soon as you publish it and view it online.
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