Hi Maribel,
Seems like you're using Joomla 2.5.x which caused some of compatibility issue
Where I've hit this error :
Catchable fatal error: Argument 1 passed to JInput::getArray() must be an array, none given, called in JoomlaFolder/components/com_easysocial/controllers/videos.php on line 245 and defined in JoomlaFolder/libraries/joomla/application/input.php on line 166
I've fix the issue in the file:
JoomlaFolder\components\com_easysocial\controllers\videos.php
$post = $this->input->post->getArray();
to
$post = $this->input->getArray('post');
Can you please have a try.
If the issue is still persist, don't hesitate to ask