diff --git a/app/voicemails/resources/classes/voicemail.php b/app/voicemails/resources/classes/voicemail.php
index bef26980f9..977123e628 100644
--- a/app/voicemails/resources/classes/voicemail.php
+++ b/app/voicemails/resources/classes/voicemail.php
@@ -291,7 +291,7 @@
 
 						//filter out unchecked sip profiles
 							foreach ($records as $x => $record) {
-								if ($record['checked'] == 'true' && is_uuid($record['uuid'])) {
+								if (!empty($record['checked']) && $record['checked'] == 'true' && is_uuid($record['uuid'])) {
 									$uuids[] = "'".$record['uuid']."'";
 								}
 							}
@@ -411,7 +411,7 @@
 
 						//filter out unchecked sip profiles
 							foreach ($records as $x => $record) {
-								if ($record['checked'] == 'true' && is_uuid($record['uuid'])) {
+								if (!empty($record['checked']) && $record['checked'] == 'true' && is_uuid($record['uuid'])) {
 									//build the delete array
 										$array[$this->table][$x][$this->uuid_prefix.'uuid'] = $record['uuid'];
 										$array[$this->table][$x]['voicemail_uuid'] = $this->voicemail_uuid;
@@ -458,7 +458,7 @@
 
 						//filter out unchecked sip profiles
 							foreach ($records as $x => $record) {
-								if ($record['checked'] == 'true' && is_uuid($record['uuid'])) {
+								if (!empty($record['checked']) && $record['checked'] == 'true' && is_uuid($record['uuid'])) {
 									//build the delete array
 										$array[$this->table][$x][$this->uuid_prefix.'uuid'] = $record['uuid'];
 										$array[$this->table][$x]['voicemail_uuid'] = $this->voicemail_uuid;
@@ -507,7 +507,7 @@
 
 						//filter out unchecked sip profiles
 							foreach ($records as $x => $record) {
-								if ($record['checked'] == 'true' && is_uuid($record['uuid'])) {
+								if (!empty($record['checked']) && $record['checked'] == 'true' && is_uuid($record['uuid'])) {
 									$uuids[] = "'".$record['uuid']."'";
 								}
 							}
@@ -748,7 +748,7 @@
 			$path = $_SESSION['switch']['voicemail']['dir'].'/default/'.$_SESSION['domain_name'].'/'.$this->voicemail_id;
 
 			//prepare base64 content from db, if enabled
-			if ($_SESSION['voicemail']['storage_type']['text'] == 'base64') {
+			if (!empty($_SESSION['voicemail']['storage_type']['text']) && $_SESSION['voicemail']['storage_type']['text'] == 'base64') {
 				$sql = "select message_base64 ";
 				$sql .= "from ";
 				$sql .= "v_voicemail_messages as m, ";
@@ -799,11 +799,6 @@
 				return false;
 			}
 
-			//content-range
-			if (isset($_SERVER['HTTP_RANGE']) && $this->type != 'bin')  {
-				$this->range_download($file_path);
-			}
-
 			$fd = fopen($file_path, "rb");
 			if ($this->type == 'bin') {
 				header("Content-Type: application/force-download");
@@ -830,10 +825,16 @@
 				header("Content-Length: ".filesize($file_path));
 			}
 			ob_end_clean();
+
+			//content-range
+			if (isset($_SERVER['HTTP_RANGE']) && $this->type != 'bin')  {
+				$this->range_download($file_path);
+			}
+
 			fpassthru($fd);
 
 			//if base64, remove temp file
-			if ($_SESSION['voicemail']['storage_type']['text'] == 'base64') {
+			if (!empty($_SESSION['voicemail']['storage_type']['text']) && $_SESSION['voicemail']['storage_type']['text'] == 'base64') {
 				@unlink($path.'/msg_'.$this->voicemail_message_uuid.'.'.$file_ext);
 			}
 
@@ -884,7 +885,7 @@
 				// If the range starts with an '-' we start from the beginning
 				// If not, we forward the file pointer
 				// And make sure to get the end byte if spesified
-				if ($range0 == '-') {
+				if (!empty($range0) && $range0 == '-') {
 					// The n-number of the last bytes is requested
 					$c_start = $size - substr($range, 1);
 				}
diff --git a/app/voicemails/resources/dashboard/voicemails.php b/app/voicemails/resources/dashboard/voicemails.php
index 8a01522499..4206425ca5 100644
--- a/app/voicemails/resources/dashboard/voicemails.php
+++ b/app/voicemails/resources/dashboard/voicemails.php
@@ -120,7 +120,7 @@
 			if (is_uuid($voicemail_uuid)) {
 				$tr_link = "href='".PROJECT_PATH."/app/voicemails/voicemail_messages.php?id=".(permission_exists('voicemail_view') ? $voicemail_uuid : $row['ext'])."'";
 				echo "<tr ".$tr_link." style='cursor: pointer;'>";
-				echo "	<td class='".$row_style[$c]." hud_text'><a href='".PROJECT_PATH."/app/voicemails/voicemail_messages.php?id=".(permission_exists('voicemail_view') ? $voicemail_uuid : $row['ext'])."'>".$row['ext']."</a></td>";
+				echo "	<td class='".$row_style[$c]." hud_text'><a href='".PROJECT_PATH."/app/voicemails/voicemail_messages.php?id=".(permission_exists('voicemail_view') ? $voicemail_uuid : $row['ext'])."&back=".urlencode($_SERVER["REQUEST_URI"])."'>".$row['ext']."</a></td>";
 				echo "	<td class='".$row_style[$c]." hud_text' style='text-align: center;'>".$row['new']."</td>";
 				echo "	<td class='".$row_style[$c]." hud_text' style='text-align: center;'>".$row['total']."</td>";
 				echo "</tr>";
diff --git a/app/voicemails/voicemail_edit.php b/app/voicemails/voicemail_edit.php
index c5301cada3..63393e24b4 100644
--- a/app/voicemails/voicemail_edit.php
+++ b/app/voicemails/voicemail_edit.php
@@ -74,7 +74,7 @@
 	if (!empty($_POST)) {
 
 		//process the http post data by submitted action
-			if ($_POST['action'] != '' && is_uuid($_POST['voicemail_uuid'])) {
+			if (!empty($_POST['action']) && is_uuid($_POST['voicemail_uuid'])) {
 				$array[0]['checked'] = 'true';
 				$array[0]['uuid'] = $_POST['voicemail_uuid'];
 
@@ -98,16 +98,16 @@
 			$voicemail_options = $_POST["voicemail_options"];
 			$voicemail_alternate_greet_id = $_POST["voicemail_alternate_greet_id"];
 			$voicemail_mail_to = $_POST["voicemail_mail_to"];
-			$voicemail_sms_to = $_POST["voicemail_sms_to"];
-			$voicemail_transcription_enabled = $_POST["voicemail_transcription_enabled"];
+			$voicemail_sms_to = $_POST["voicemail_sms_to"] ?? null;
+			$voicemail_transcription_enabled = $_POST["voicemail_transcription_enabled"] ?? null;
 			$voicemail_file = $_POST["voicemail_file"];
 			$voicemail_local_after_email = $_POST["voicemail_local_after_email"];
 			$voicemail_destination = $_POST["voicemail_destination"];
 			$voicemail_enabled = $_POST["voicemail_enabled"] ?? 'false';
 			$voicemail_description = $_POST["voicemail_description"];
 			$voicemail_tutorial = $_POST["voicemail_tutorial"];
-			$voicemail_options_delete = $_POST["voicemail_options_delete"];
-			$voicemail_destinations_delete = $_POST["voicemail_destinations_delete"];
+			$voicemail_options_delete = $_POST["voicemail_options_delete"] ?? null;
+			$voicemail_destinations_delete = $_POST["voicemail_destinations_delete"] ?? null;
 
 		//remove the space
 			$voicemail_mail_to = str_replace(" ", "", $voicemail_mail_to);
@@ -211,7 +211,7 @@
 								$array['voicemail_options'][$x]['voicemail_option_order'] = $voicemail_option['voicemail_option_order'];
 								$array['voicemail_options'][$x]['voicemail_option_description'] = $voicemail_option['voicemail_option_description'];
 						}
-						if (is_array($array['voicemail_options']) && @sizeof($array['voicemail_options']) != 0) {
+						if (!empty($array['voicemail_options']) && is_array($array['voicemail_options']) && @sizeof($array['voicemail_options']) != 0) {
 							//grant temporary permission
 								$p->add('voicemail_option_add', 'temp');
 						}
@@ -540,7 +540,7 @@
 	echo "<td class='vtable' align='left'>\n";
 	echo "	<select class='formfld' name='greeting_id'>\n";
 	echo "		<option value=''>".$text['label-default']."</option>\n";
-	echo "		<option value='0' ".(($greeting_id == "0") ? "selected='selected'" : null).">".$text['label-none']."</option>\n";
+	echo "		<option value='0' ".(empty($greeting_id) || $greeting_id == "0" ? "selected='selected'" : null).">".$text['label-none']."</option>\n";
 	if (is_array($greetings) && @sizeof($greetings) != 0) {
 		foreach ($greetings as $greeting) {
 			$selected = ($greeting['greeting_id'] == $greeting_id) ? 'selected' : null;
@@ -611,7 +611,7 @@
 			echo "	</td>\n";
 			echo "	<td class='vtable' style='border-bottom: none;' align='left'>\n";
 			echo "		<select name='voicemail_options[".$c."][voicemail_option_order]' class='formfld' style='width:55px'>\n";
-			if (strlen(htmlspecialchars($voicemail_option_order))> 0) {
+			if (strlen(htmlspecialchars($voicemail_option_order ?? ''))> 0) {
 				echo "		<option selected='yes' value='".htmlspecialchars($voicemail_option_order)."'>".htmlspecialchars($voicemail_option_order)."</option>\n";
 			}
 			$i = 0;
diff --git a/app/voicemails/voicemail_messages.php b/app/voicemails/voicemail_messages.php
index 052e96de7a..806f74f258 100644
--- a/app/voicemails/voicemail_messages.php
+++ b/app/voicemails/voicemail_messages.php
@@ -41,7 +41,7 @@
 		) {
 		$voicemail = new voicemail;
 		$voicemail->domain_uuid = $_SESSION['domain_uuid'];
-		$voicemail->type = $_REQUEST['t'];
+		$voicemail->type = $_REQUEST['t'] ?? null;
 		$voicemail->voicemail_id = $_REQUEST['id'];
 		$voicemail->voicemail_uuid = $_REQUEST['voicemail_uuid'];
 		$voicemail->voicemail_message_uuid = $_REQUEST['uuid'];
@@ -64,11 +64,14 @@
 		exit;
 	}
 
+//set the back button url
+	$_SESSION['back'][$_SERVER['PHP_SELF']] = !empty($_GET['back']) ? urldecode($_GET['back']) : ($_SESSION['back'][$_SERVER['PHP_SELF']] ?? PROJECT_PATH.'/app/voicemails/voicemails.php');
+
 //set the voicemail_uuid
-	if (is_uuid($_REQUEST['id'])) {
+	if (!empty($_REQUEST['id']) && is_uuid($_REQUEST['id'])) {
 		$voicemail_uuid = $_REQUEST['id'];
 	}
-	else if (is_numeric($_REQUEST['id'])) {
+	else if (!empty($_REQUEST['id']) && is_numeric($_REQUEST['id'])) {
 		$voicemail_id = $_REQUEST['id'];
 	}
 
@@ -105,7 +108,7 @@
 					if (is_array($voicemail_messages) && @sizeof($voicemail_messages) != 0) {
 						$messages_toggled = 0;
 						foreach ($voicemail_messages as $voicemail_message) {
-							if ($voicemail_message['checked'] == 'true' && is_uuid($voicemail_message['uuid']) && is_uuid($voicemail_message['voicemail_uuid'])) {
+							if (!empty($voicemail_message['checked']) && $voicemail_message['checked'] == 'true' && is_uuid($voicemail_message['uuid']) && is_uuid($voicemail_message['voicemail_uuid'])) {
 								//delete voicemail message
 									$voicemail = new voicemail;
 									$voicemail->db = $db;
@@ -129,7 +132,7 @@
 						if (is_array($voicemail_messages) && @sizeof($voicemail_messages) != 0) {
 							$messages_deleted = 0;
 							foreach ($voicemail_messages as $voicemail_message) {
-								if ($voicemail_message['checked'] == 'true' && is_uuid($voicemail_message['uuid']) && is_uuid($voicemail_message['voicemail_uuid'])) {
+								if (!empty($voicemail_message['checked']) && $voicemail_message['checked'] == 'true' && is_uuid($voicemail_message['uuid']) && is_uuid($voicemail_message['voicemail_uuid'])) {
 									//delete voicemail message
 										$voicemail = new voicemail;
 										$voicemail->db = $db;
@@ -172,10 +175,10 @@
 //get the voicemail
 	$vm = new voicemail;
 	$vm->domain_uuid = $_SESSION['domain_uuid'];
-	if (is_uuid($voicemail_uuid)) {
+	if (!empty($voicemail_uuid) && is_uuid($voicemail_uuid)) {
 		$vm->voicemail_uuid = $voicemail_uuid;
 	}
-	else if (is_numeric($voicemail_id)) {
+	else if (!empty($voicemail_id) && is_numeric($voicemail_id)) {
 		$vm->voicemail_id = $voicemail_id;
 	}
 	$vm->order_by = $order_by;
@@ -209,11 +212,12 @@
 	echo "<div class='action_bar' id='action_bar'>\n";
 	echo "	<div class='heading'><b>".$text['title-voicemail_messages']." (".$num_rows.")</b></div>\n";
 	echo "	<div class='actions'>\n";
+	echo button::create(['type'=>'button','label'=>$text['button-back'],'icon'=>$_SESSION['theme']['button_icon_back'],'id'=>'btn_back','link'=>$_SESSION['back'][$_SERVER['PHP_SELF']]]);
 	if ($num_rows) {
-		echo button::create(['type'=>'button','label'=>$text['button-toggle'],'icon'=>$_SESSION['theme']['button_icon_toggle'],'name'=>'btn_toggle','collapse'=>'hide-xs','onclick'=>"modal_open('modal-toggle','btn_toggle');"]);
+		echo button::create(['type'=>'button','label'=>$text['button-toggle'],'icon'=>$_SESSION['theme']['button_icon_toggle'],'id'=>'btn_toggle','name'=>'btn_toggle','collapse'=>'hide-xs','style'=>'margin-left: 15px; display: none;','onclick'=>"modal_open('modal-toggle','btn_toggle');"]);
 	}
 	if (permission_exists('voicemail_message_delete') && $num_rows) {
-		echo button::create(['type'=>'button','label'=>$text['button-delete'],'icon'=>$_SESSION['theme']['button_icon_delete'],'name'=>'btn_delete','collapse'=>'hide-xs','onclick'=>"modal_open('modal-delete','btn_delete');"]);
+		echo button::create(['type'=>'button','label'=>$text['button-delete'],'icon'=>$_SESSION['theme']['button_icon_delete'],'id'=>'btn_delete','name'=>'btn_delete','collapse'=>'hide-xs','style'=>'display: none;','onclick'=>"modal_open('modal-delete','btn_delete');"]);
 	}
 	echo "	</div>\n";
 	echo "	<div style='clear: both;'></div>\n";
@@ -268,7 +272,7 @@
 				$col_count = 0;
 				if (permission_exists('voicemail_message_delete')) {
 					echo "	<th class='checkbox'>\n";
-					echo "		<input type='checkbox' id='checkbox_all_".$field['voicemail_id']."' name='checkbox_all' onclick=\"list_all_toggle('".$field['voicemail_id']."');\" ".(is_array($field['messages']) && @sizeof($field['messages']) > 0 ?: "style='visibility: hidden;'").">\n";
+					echo "		<input type='checkbox' id='checkbox_all_".$field['voicemail_id']."' name='checkbox_all' onclick=\"list_all_toggle('".$field['voicemail_id']."'); checkbox_on_change(this);\" ".(is_array($field['messages']) && @sizeof($field['messages']) > 0 ?: "style='visibility: hidden;'").">\n";
 					echo "	</th>\n";
 					$col_count++;
 				}
@@ -282,7 +286,7 @@
 				$col_count++;
 				echo th_order_by('message_length', $text['label-message_length'], $order_by, $order, null, "class='hide-xs right pct-15'");
 				$col_count++;
-				if (!empty($_SESSION['voicemail']['storage_type']['text']) != 'base64') {
+				if (empty($_SESSION['voicemail']['storage_type']['text']) || $_SESSION['voicemail']['storage_type']['text'] != 'base64') {
 					echo "<th class='right pct-15 hide-sm-dn'>".$text['label-message_size']."</th>\n";
 					$col_count++;
 				}
@@ -300,7 +304,7 @@
 					$list_row_url = "javascript:recording_play('".escape($row['voicemail_message_uuid'])."');";
 					echo "<tr class='list-row' href=\"".$list_row_url."\">\n";
 					echo "	<td class='checkbox'>\n";
-					echo "		<input type='checkbox' name='voicemail_messages[$x][checked]' id='checkbox_".$x."' class='checkbox_".$field['voicemail_id']."' value='true' onclick=\"if (!this.checked) { document.getElementById('checkbox_all_".$field['voicemail_id']."').checked = false; }\">\n";
+					echo "		<input type='checkbox' name='voicemail_messages[$x][checked]' id='checkbox_".$x."' class='checkbox_".$field['voicemail_id']."' value='true' onclick=\"if (!this.checked) { document.getElementById('checkbox_all_".$field['voicemail_id']."').checked = false; } checkbox_on_change(this);\">\n";
 					echo "		<input type='hidden' name='voicemail_messages[$x][uuid]' value='".escape($row['voicemail_message_uuid'])."' />\n";
 					echo "		<input type='hidden' name='voicemail_messages[$x][voicemail_uuid]' value='".escape($row['voicemail_uuid'])."' />\n";
 					echo "	</td>\n";
@@ -316,7 +320,7 @@
 					}
 					echo "	</td>\n";
 					echo "	<td class='right no-wrap hide-xs' style='".$bold."'>".escape($row['message_length_label'])."</td>\n";
-					if (!empty($_SESSION['voicemail']['storage_type']['text']) != 'base64') {
+					if (empty($_SESSION['voicemail']['storage_type']['text']) || $_SESSION['voicemail']['storage_type']['text'] != 'base64') {
 						echo "	<td class='right no-wrap hide-sm-dn' style='".$bold."'>".escape($row['file_size_label'])."</td>\n";
 					}
 					echo "</tr>\n";
@@ -372,4 +376,4 @@
 //include the footer
 	require_once "resources/footer.php";
 
-?>
+?>
\ No newline at end of file
diff --git a/app/voicemails/voicemails.php b/app/voicemails/voicemails.php
index f4ee910519..675581e739 100644
--- a/app/voicemails/voicemails.php
+++ b/app/voicemails/voicemails.php
@@ -307,7 +307,7 @@
 				}
 				if (permission_exists('voicemail_message_view')) {
 					$tmp_voicemail_string = (array_key_exists($row['voicemail_uuid'], $voicemails_count)) ? " (" . $voicemails_count[$row['voicemail_uuid']] . ")" : " (0)";
-					echo "	<a href='voicemail_messages.php?id=".escape($row['voicemail_uuid'])."'>".$text['label-messages'].$tmp_voicemail_string."</a>\n";
+					echo "	<a href='voicemail_messages.php?id=".escape($row['voicemail_uuid'])."&back=".urlencode($_SERVER["REQUEST_URI"])."'>".$text['label-messages'].$tmp_voicemail_string."</a>\n";
 				}
 				echo "	</td>\n";
 			}