Hello Helder Cortez,

May i know do you have install JomSocial extension in your site?
If yes, try update to latest version of JomSocial extension and see how it goes.

If no, can you provide us with your Joomla backend and FTP access so we can help you check on this? Please advise.
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I have disabled joomsocial -still not working - I can't publish anything using the frontend.
Information sent

Also, my user assigned as PUBLISHER and MANAGER can't post anything using the frontend dashboard,.

Interesting, I have uninstalled jomsocial but it is still available in the backend.

I think (not sure) it's working after I deleted the _community folder via FTP - but I still can't post videos. I get a blank screen and when I try using the link it shows a messed up embed code instead of the video.

Hello Helder Cortez,

I'm really sorry that delayed of this reply,
If I'm not wrong that issues already fixes in latest version of JomSocial, the reason why this related is because when you publishing a blog post, the JomSocial wall will show out the blog post stream.

Regarding with your youtube video can't shown in your blog post :
>> It seems like when you send the data to your server, but it return back this, do you have noticed there auto added backslash "\" ?

[embed=videolink]{\"video\":\"http://www.youtube.com/watch?v=2ih3WYlTzlQ\",\"width\":\"400\",\"height\":\"225\"}[/embed]

Can you request with your Webhosting provider to switch off all the magic_quotes from your frontend/backend php information and see how it goes? Please advise.