diff --git a/calendar/inc/class.calendar_boupdate.inc.php b/calendar/inc/class.calendar_boupdate.inc.php
index 1baab6e0e5..b2c9621e84 100644
--- a/calendar/inc/class.calendar_boupdate.inc.php
+++ b/calendar/inc/class.calendar_boupdate.inc.php
@@ -114,6 +114,7 @@ class calendar_boupdate extends calendar_bo
 	function update(&$event,$ignore_conflicts=false,$touch_modified=true,$ignore_acl=false,$updateTS=true,&$messages=null, $skip_notification=false)
 	{
 		//error_log(__METHOD__."(".array2string($event).",$ignore_conflicts,$touch_modified,$ignore_acl)");
+		if (!is_array($messages)) $messages = $messages ? (array)$messages : array();
 
 		if ($this->debug > 1 || $this->debug == 'update')
 		{
@@ -127,6 +128,7 @@ class calendar_boupdate extends calendar_bo
 			$event['id'] && (isset($event['start']) && !$event['start'] || isset($event['end']) && !$event['end'] ||
 			isset($event['title']) && !$event['title']))
 		{
+			$messages[] = lang('Required information (start, end, title, ...) missing!');
 			return false;
 		}
 
@@ -150,6 +152,7 @@ class calendar_boupdate extends calendar_bo
 			$new_event && !$this->check_perms(EGW_ACL_EDIT,0,$event['owner'])) &&
 			!$this->check_perms(EGW_ACL_ADD,0,$event['owner']))
 		{
+			$messages[] = lang('Access to calendar of %1 denied!',common::grab_owner_name($event['owner']));
 			return false;
 		}
 		if ($new_event)
diff --git a/calendar/inc/class.calendar_uiforms.inc.php b/calendar/inc/class.calendar_uiforms.inc.php
index 52498a9c6d..d09f0bc4ec 100644
--- a/calendar/inc/class.calendar_uiforms.inc.php
+++ b/calendar/inc/class.calendar_uiforms.inc.php
@@ -1723,14 +1723,22 @@ function replace_eTemplate_onsubmit()
 					$status = strtoupper($button[0]);	// A, R or T
 					if (!$event['id'])
 					{
+						// if organizer is a EGroupware user, but we have no rights to organizers calendar
+						if (isset($event['owner']) && !$this->bo->check_perms(EGW_ACL_ADD,0,$event['owner']))
+						{
+							// --> make organize a participant with role chair and current user the owner
+							$event['participant_types']['u'] = $event['participants'][$event['owner']] =
+								calendar_so::combine_status('A', 1, 'CHAIR');
+							$event['owner'] = $this->user;
+						}
 						// store event without notifications!
 						if (($event['id'] = $this->bo->update($event, $ignore_conflicts=true, true, false, true, $msg, true)))
 						{
-							$msg = lang('Event saved');
+							$msg[] = lang('Event saved');
 						}
 						else
 						{
-							$msg = lang('Error: saving the event !!!');
+							$msg[] = lang('Error saving the event!');
 							break;
 						}
 					}
@@ -1742,7 +1750,7 @@ function replace_eTemplate_onsubmit()
 					break;
 			}
 		}
-		$event['msg'] = $msg;
+		$event['msg'] = implode("\n",(array)$msg);
 		$readonlys['button[edit]'] = !$event['id'];
 
 		$tpl = new etemplate('calendar.meeting');
diff --git a/calendar/lang/egw_de.lang b/calendar/lang/egw_de.lang
index e3dfae16d9..3107129723 100644
--- a/calendar/lang/egw_de.lang
+++ b/calendar/lang/egw_de.lang
@@ -14,6 +14,7 @@ accept	calendar	de	Zusagen
 accept or reject an invitation	calendar	de	Einladung zu- oder absagen
 accepted	calendar	de	Zugesagt
 access denied to the calendar of %1 !!!	calendar	de	Zugriff zum Kalender von %1 verweigert !!!
+access to calendar of %1 denied!	calendar	de	Zugriff auf den Kalender von %1 verweigert!
 action that caused the notify: added, canceled, accepted, rejected, ...	calendar	de	Aktion, welche die Benachrichtigung verursacht hat: Zugefügt, Storniert, Zugesagt, Abgesagt
 actions	calendar	de	Befehle
 actions...	calendar	de	Aktionen...
@@ -375,6 +376,7 @@ requested	calendar	de	Erforderlich
 requested date %1 outside allowed range of %2 days: recurring events obmitted!	calendar	de	Gewünschtes Datum %1 außerhalb des erlauben Bereiches von %2 Tagen: wiederholdende Termine ausgelassen!
 requested meeting is in the past!	calendar	de	Termin, zu dem eingeladen wird, ist in der Vergangenheit!
 require an acl grant to invite other users and groups	admin	de	Freigabe um andere Benutzer oder Gruppen einzuladen erforderlich
+required information (start, end, title, ...) missing!	calendar	de	Zwingend erforderliche Information (Start, Ende, Titel, ...) fehlen!
 reset	calendar	de	Zurücksetzen
 reset participant stati on event shifts	calendar	de	Rücksetzen des Teilnehmerstatus beim Verschieben von Terminen
 resources	calendar	de	Ressourcen
diff --git a/calendar/lang/egw_en.lang b/calendar/lang/egw_en.lang
index 03818a5b2d..3e7e81d155 100644
--- a/calendar/lang/egw_en.lang
+++ b/calendar/lang/egw_en.lang
@@ -14,6 +14,7 @@ accept	calendar	en	Accept
 accept or reject an invitation	calendar	en	Accept or reject an invitation
 accepted	calendar	en	Accepted
 access denied to the calendar of %1 !!!	calendar	en	Access denied to the calendar of %1 !
+access to calendar of %1 denied!	calendar	en	Access to calendar of %1 denied!
 action that caused the notify: added, canceled, accepted, rejected, ...	calendar	en	Action that caused the notify: Added, Canceled, Accepted, Rejected, ...
 actions	calendar	en	Actions
 actions...	calendar	en	Actions...
@@ -375,6 +376,7 @@ requested	calendar	en	Requested
 requested date %1 outside allowed range of %2 days: recurring events obmitted!	calendar	en	Requested date %1 outside allowed range of %2 days: recurring events obmitted!
 requested meeting is in the past!	calendar	en	Requested meeting is in the past!
 require an acl grant to invite other users and groups	admin	en	Require an ACL grant to invite other users and groups
+required information (start, end, title, ...) missing!	calendar	en	Required information (start, end, title, ...) missing!
 reset	calendar	en	Reset
 reset participant stati on event shifts	calendar	en	Reset participant status on event shifts
 resources	calendar	en	Resources