Hi. First of all you are using an outdated version of AllVideos. You should update to 4.6.1. Second, AllVideos is not breaking your site or blocking anything. You have placed invalid HTML markup on your page. That's why your site is broken. Try to check again the editor contents again. Look at the source and remove all invalid markup.
JoomlaWorks Support Team
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Please search the forum before posting a new topic :)