blast

Roll back to php 5.5 and it works like a charm.

With PHP 5.6 I added this line to php.ini

always_populate_raw_post_data = -1 

I try to investigate but first I show you the errors.

The ajax return:

<br />
<b>Deprecated</b>:  Automatically populating $HTTP_RAW_POST_DATA is deprecated and will be removed in a future version. To avoid this warning set 'always_populate_raw_post_data' to '-1' in php.ini and use the php://input stream instead. in <b>Unknown</b> on line <b>0</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent in <b>Unknown</b> on line <b>0</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent in <b>/Users/andreamontaldo/Sites/siae-promo/web/wire/core/admin.php</b> on line <b>15</b><br />
[{"error":false,"message":"Added file: dsc00181.jpg","file":"\/siae-promo\/web\/site\/assets\/files\/1023\/dsc00181.jpg","size":98458,"markup":"\n\t<li id='file_3dbec45f3f9fb3712c4ac718c1f1ba9b' class='InputfieldFileItem InputfieldImage ui-widget'>\n\t\t<p class='InputfieldFileInfo InputfieldItemHeader ui-widget ui-widget-header'>\n\t\t\t<i class='fa fa-fw fa-sort HideIfSingle'><\/i>\n\t\t\t<i class='fa fa-fw fa-caret-right HideIfMultiple'><\/i> \n\t\t\t<a class='InputfieldFileName pw-modal pw-modal-large' title='dsc00181.jpg (1623x1080)' href='\/siae-promo\/web\/gestione\/page\/image\/edit\/?id=1023&file=1023,dsc00181.jpg&rte=0&field=cover' data-buttons='#non_rte_dialog_buttons button' data-autoclose='1' data-close='#non_rte_cancel'>dsc00181.jpg <i class='fa fa-pencil ui-priority-secondary'><\/i><\/a> \n\t\t\t<span class='InputfieldFileStats'>96 kB, 1623x1080  <\/span> \n\t\t\t<label class='InputfieldFileDelete'><input type='checkbox' name='delete_cover_3dbec45f3f9fb3712c4ac718c1f1ba9b' value='1' title='Delete' \/><i class='fa fa-fw fa-trash'><\/i><\/label>\n\t\t\t<a class='InputfieldFileMove InputfieldFileMoveBottom' href='#' title='Move to bottom'><i class='fa fa-fw fa-angle-double-down'><\/i><\/a> \n\t\t\t<a class='InputfieldFileMove InputfieldFileMoveTop' href='#' title='Move to top'><i class='fa fa-fw fa-angle-double-up'><\/i><\/a> \n\t\t<\/p>\n\t\t<div class='InputfieldFileData ui-widget ui-widget-content'>\n\t\t\t<div class='InputfieldImagePreview'>\n\t\t\t\t<a class='InputfieldFileLink' target='_blank' href='\/siae-promo\/web\/site\/assets\/files\/1023\/dsc00181.jpg?nc=1429127148'><img height=\"50\" src=\"\/siae-promo\/web\/site\/assets\/files\/1023\/dsc00181.0x100.jpg?nc=1429127149\" alt=\"\" data-gridsize=\"50\"  \/><\/a>\n\t\t\t\t<div class='InputfieldImageActions'>\n\t\t\t\t\t<a title='dsc00181.jpg (1623x1080)' href='\/siae-promo\/web\/gestione\/page\/image\/edit\/?id=1023&file=1023,dsc00181.jpg&rte=0&field=cover' class='pw-modal pw-modal-large' data-buttons='#non_rte_dialog_buttons button' data-autoclose='1' data-close='#non_rte_cancel'><i class='fa fa-fw fa-crop'><\/i><\/a>\n\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t\t<div class='InputfieldFileDescription'><label for='description_cover_3dbec45f3f9fb3712c4ac718c1f1ba9b' class='detail'>Description<\/label><input type='text' name='description_cover_3dbec45f3f9fb3712c4ac718c1f1ba9b' id='description_cover_3dbec45f3f9fb3712c4ac718c1f1ba9b' value='' \/><\/div>\n\t\t\t<input class='InputfieldFileSort' type='text' name='sort_cover_3dbec45f3f9fb3712c4ac718c1f1ba9b' value='0' \/>\n\t\t<\/div>\n\t\t\t<div class='ui-widget-content crops'><p class='description'>Thumbnails (hover to preview, click to crop)<\/p><a target='_blank' data-thumburl='\/siae-promo\/web\/site\/assets\/files\/1023\/thumbnail_dsc00181.jpg' class='crop' href='\/siae-promo\/web\/gestione\/page\/image-crop\/?filename=dsc00181.jpg&prefix=thumbnail&width=100&height=100&pages_id=1023&field=cover&modal=1'>thumbnail<\/a><\/div>\n\t<\/li>","replace":false,"overwrite":0}]

The PHP logs:

[15-Apr-2015 21:45:34 Europe/Rome] PHP Deprecated:  Automatically populating $HTTP_RAW_POST_DATA is deprecated and will be removed in a future version. To avoid this warning set 'always_populate_raw_post_data' to '-1' in php.ini and use the php://input stream instead. in Unknown on line 0
[15-Apr-2015 21:45:34 Europe/Rome] PHP Warning:  Cannot modify header information - headers already sent in Unknown on line 0
[15-Apr-2015 21:45:34 Europe/Rome] PHP Warning:  Cannot modify header information - headers already sent in /Users/andreamontaldo/Sites/siae-promo/web/wire/core/admin.php on line 15
[15-Apr-2015 21:46:41 Europe/Rome] PHP Notice:  Undefined index: id in /Users/andreamontaldo/Sites/siae-promo/web/wire/core/Process.php on line 313
[15-Apr-2015 21:46:41 Europe/Rome] PHP Notice:  Undefined index: id in /Users/andreamontaldo/Sites/siae-promo/web/wire/core/Process.php on line 313
[15-Apr-2015 21:46:41 Europe/Rome] PHP Notice:  Undefined index: id in /Users/andreamontaldo/Sites/siae-promo/web/wire/core/Process.php on line 313
[15-Apr-2015 21:46:41 Europe/Rome] PHP Notice:  Undefined index: id in /Users/andreamontaldo/Sites/siae-promo/web/wire/core/Process.php on line 313
[15-Apr-2015 21:46:41 Europe/Rome] PHP Notice:  Undefined index: id in /Users/andreamontaldo/Sites/siae-promo/web/wire/core/Process.php on line 313

Same problem here, it only works if I launch InitOldSchool();

Try commenting all the session's configuration in index.php

	// session_name($config->sessionName); 
	// ini_set('session.use_cookies', true); 
	// ini_set('session.use_only_cookies', 1);
	// ini_set("session.gc_maxlifetime", $config->sessionExpireSeconds); 
	// ini_set("session.save_path", rtrim($config->paths->sessions, '/')); 

It worked for me.