2 14 Feb 2015 12:01
I guess that inserting HTML code into the description is not allowed by security reasons. However, line breaks are automatically created if you add the caption to the image using the "Meta data method" (http://b2evolution.net/man/file-properties). All the text written in the "Caption/Description" field will be displayed as the caption of the image at the front-end (including the line breaks). Of course, if you use the "inline tag method" (http://b2evolution.net/man/image-short-tag) it is not possible.
Just a little tip, if you need to accept html code in the description of your files, go to inc/files/files.ctrl.php and replace the line
$edited_File->set( 'desc', param( 'desc', 'text', '' ) );
with this other
$edited_File->set( 'desc', param( 'desc', 'html', '' ) );
As always, I must say that core hacks are not recommended, but you are free to do it if you want to (open source + free software benefits :D).