diff --git a/phpBB/docs/CHANGELOG.html b/phpBB/docs/CHANGELOG.html
index 071e98a641..de6a6fcadd 100644
--- a/phpBB/docs/CHANGELOG.html
+++ b/phpBB/docs/CHANGELOG.html
@@ -116,6 +116,7 @@
 		<li>[Fix] Correctly check for empty strings in custom profile fields. (Bug #55335)</li>
 		<li>[Fix] Use correct options to parse BBCodes in signatures when previewing PMs.</li>
 		<li>[Fix] Correct rendering of prosilver quick reply under IE6. (Bug #54115 - Patch by Raimon)</li>
+		<li>[Fix] Handle export of private messages where all recipients were deleted. (Bug #50985)</li>
 		<li>[Change] Log activation through inactive users ACP. (Bug #30145)</li>
 		<li>[Change] Send time of last item instead of current time in ATOM Feeds. (Bug #53305)</li>
 		<li>[Change] Use em dash instead of hyphen/minus as separator in ATOM Feeds item statistics. (Bug #53565)</li>
diff --git a/phpBB/includes/ucp/ucp_pm_viewfolder.php b/phpBB/includes/ucp/ucp_pm_viewfolder.php
index 06852db591..665dd2c83f 100644
--- a/phpBB/includes/ucp/ucp_pm_viewfolder.php
+++ b/phpBB/includes/ucp/ucp_pm_viewfolder.php
@@ -200,13 +200,15 @@ function view_folder($id, $mode, $folder_id, $folder)
 		else
 		{
 			// Build Recipient List if in outbox/sentbox
-			$address = $data = array();
+
+			$address_temp = $address = $data = array();
 
 			if ($folder_id == PRIVMSGS_OUTBOX || $folder_id == PRIVMSGS_SENTBOX)
 			{
 				foreach ($folder_info['rowset'] as $message_id => $row)
 				{
-					$address[$message_id] = rebuild_header(array('to' => $row['to_address'], 'bcc' => $row['bcc_address']));
+					$address_temp[$message_id] = rebuild_header(array('to' => $row['to_address'], 'bcc' => $row['bcc_address']));
+					$address[$message_id] = array();
 				}
 			}
 
@@ -230,8 +232,12 @@ function view_folder($id, $mode, $folder_id, $folder)
 				$_types = array('u', 'g');
 				foreach ($_types as $ug_type)
 				{
-					if (isset($address[$message_id][$ug_type]) && sizeof($address[$message_id][$ug_type]))
+					if (isset($address_temp[$message_id][$ug_type]) && sizeof($address_temp[$message_id][$ug_type]))
 					{
+						if (!isset($address[$message_id][$ug_type]))
+						{
+							$address[$message_id][$ug_type] = array();
+						}
 						if ($ug_type == 'u')
 						{
 							$sql = 'SELECT user_id as id, username as name
@@ -244,21 +250,31 @@ function view_folder($id, $mode, $folder_id, $folder)
 								FROM ' . GROUPS_TABLE . '
 								WHERE ';
 						}
-						$sql .= $db->sql_in_set(($ug_type == 'u') ? 'user_id' : 'group_id', array_map('intval', array_keys($address[$message_id][$ug_type])));
+						$sql .= $db->sql_in_set(($ug_type == 'u') ? 'user_id' : 'group_id', array_map('intval', array_keys($address_temp[$message_id][$ug_type])));
 
 						$result = $db->sql_query($sql);
 
 						while ($info_row = $db->sql_fetchrow($result))
 						{
-							$address[$message_id][$ug_type][$address[$message_id][$ug_type][$info_row['id']]][] = $info_row['name'];
-							unset($address[$message_id][$ug_type][$info_row['id']]);
+							$address[$message_id][$ug_type][$address_temp[$message_id][$ug_type][$info_row['id']]][] = $info_row['name'];
+							unset($address_temp[$message_id][$ug_type][$info_row['id']]);
 						}
 						$db->sql_freeresult($result);
 					}
 				}
 
-				decode_message($message_row['message_text'], $message_row['bbcode_uid']);
+				// There is the chance that all recipients of the message got deleted. To avoid creating 
+				// exports without recipients, we add a bogus "undisclosed recipient".
+				if (!(isset($address[$message_id]['g']) && sizeof($address[$message_id]['g'])) && 
+				    !(isset($address[$message_id]['u']) && sizeof($address[$message_id]['u'])))
+				{
+					$address[$message_id]['u'] = array();
+					$address[$message_id]['u']['to'] = array();
+					$address[$message_id]['u']['to'][] = $user->lang['UNDISCLOSED_RECIPIENT'];
+				}
 
+				decode_message($message_row['message_text'], $message_row['bbcode_uid']);
+				
 				$data[] = array(
 					'subject'	=> censor_text($row['message_subject']),
 					'sender'	=> $row['username'],
diff --git a/phpBB/language/en/ucp.php b/phpBB/language/en/ucp.php
index 4b79a4b6ca..02b8a282d9 100644
--- a/phpBB/language/en/ucp.php
+++ b/phpBB/language/en/ucp.php
@@ -460,6 +460,7 @@ $lang = array_merge($lang, array(
 	'UCP_ZEBRA'						=> 'Friends &amp; Foes',
 	'UCP_ZEBRA_FOES'				=> 'Manage foes',
 	'UCP_ZEBRA_FRIENDS'				=> 'Manage friends',
+	'UNDISCLOSED_RECIPIENT'			=> 'Undisclosed Recipient',
 	'UNKNOWN_FOLDER'				=> 'Unknown folder',
 	'UNWATCH_MARKED'				=> 'Unwatch marked',
 	'UPLOAD_AVATAR_FILE'			=> 'Upload from your machine',