diff --git a/classes/context/Context.class.php b/classes/context/Context.class.php
index 1fbf807a4..22c64a8bf 100644
--- a/classes/context/Context.class.php
+++ b/classes/context/Context.class.php
@@ -1686,7 +1686,7 @@ class Context
 			for($i = 0; $i < $num_args; $i += 2)
 			{
 				$key = $args_list[$i];
-				$val = trim($args_list[$i + 1]);
+				$val = trim($args_list[$i + 1] ?? '');
 				if ($val === '')
 				{
 					unset($get_vars[$key]);
diff --git a/classes/display/HTMLDisplayHandler.php b/classes/display/HTMLDisplayHandler.php
index 325d90306..d47da79a0 100644
--- a/classes/display/HTMLDisplayHandler.php
+++ b/classes/display/HTMLDisplayHandler.php
@@ -107,7 +107,8 @@ class HTMLDisplayHandler
 				'dispPageAdminMobileContentModify' => true,
 				'dispPageAdminMobileContent' => true,
 			);
-			if(Context::get('module') != 'admin' && strpos(Context::get('act'), 'Admin') > 0 && !isset($x_exclude_actions[Context::get('act')]))
+			$current_act = Context::get('act') ?? '';
+			if(Context::get('module') != 'admin' && strpos($current_act, 'Admin') !== false && !isset($x_exclude_actions[$current_act]))
 			{
 				$output = '<div class="x">' . $output . '</div>';
 			}
diff --git a/classes/module/ModuleHandler.class.php b/classes/module/ModuleHandler.class.php
index 95ab2e073..69f3b697f 100644
--- a/classes/module/ModuleHandler.class.php
+++ b/classes/module/ModuleHandler.class.php
@@ -1109,7 +1109,7 @@ class ModuleHandler extends Handler
 						{
 							if($val->type == 'image')
 							{
-								if(strncmp('./files/attach/images/', $val->value, 22) === 0)
+								if(strncmp('./files/attach/images/', $val->value ?? '', 22) === 0)
 								{
 									$val->value = Context::getRequestUri() . substr($val->value, 2);
 								}
diff --git a/classes/page/PageHandler.class.php b/classes/page/PageHandler.class.php
index d714c8637..fd49df525 100644
--- a/classes/page/PageHandler.class.php
+++ b/classes/page/PageHandler.class.php
@@ -100,7 +100,7 @@ class PageHandler extends Handler implements Iterator
 	 * 
 	 * @return void
 	 */
-	public function rewind()
+	public function rewind(): void
 	{
 		$this->point = 0;
 	}
@@ -141,7 +141,7 @@ class PageHandler extends Handler implements Iterator
 	 * 
 	 * @return void
 	 */
-	public function next()
+	public function next(): void
 	{
 		$this->point++;
 	}
diff --git a/common/framework/parsers/EditorComponentParser.php b/common/framework/parsers/EditorComponentParser.php
index 0ab4c73fd..8c138f315 100644
--- a/common/framework/parsers/EditorComponentParser.php
+++ b/common/framework/parsers/EditorComponentParser.php
@@ -34,19 +34,19 @@ class EditorComponentParser extends BaseParser
 		// Get basic information.
 		$info->title = self::_getChildrenByLang($xml, 'title', $lang);
 		$info->description = self::_getChildrenByLang($xml, 'description', $lang);
-		$info->version = trim($xml->version);
+		$info->version = trim($xml->version ?? '');
 		$info->date = date('Ymd', strtotime($xml->date . 'T12:00:00Z'));
-		$info->homepage = trim($xml->homepage);
-		$info->license = trim($xml->license);
-		$info->license_link = trim($xml->license['link']);
+		$info->homepage = trim($xml->homepage ?? '');
+		$info->license = trim($xml->license ?? '');
+		$info->license_link = trim($xml->license['link'] ?? '');
 		$info->author = array();
 		
 		foreach ($xml->author as $author)
 		{
 			$author_info = new \stdClass;
 			$author_info->name = self::_getChildrenByLang($author, 'name', $lang);
-			$author_info->email_address = trim($author['email_address']);
-			$author_info->homepage = trim($author['link']);
+			$author_info->email_address = trim($author['email_address'] ?? '');
+			$author_info->homepage = trim($author['link'] ?? '');
 			$info->author[] = $author_info;
 		}
 		
diff --git a/common/functions.php b/common/functions.php
index 42673fb97..e4290344f 100644
--- a/common/functions.php
+++ b/common/functions.php
@@ -257,7 +257,7 @@ function escape_dqstr($str)
  */
 function explode_with_escape($delimiter, $str, $limit = 0, $escape_char = '\\')
 {
-	if ($limit < 1) $limit = null;
+	if ($limit < 1) $limit = 0;
 	$result = array();
 	$split = preg_split('/(?<!' . preg_quote($escape_char, '/') . ')' . preg_quote($delimiter, '/') . '/', $str, $limit);
 	foreach ($split as $piece)
diff --git a/common/legacy.php b/common/legacy.php
index a13ac7b47..eb3e74317 100644
--- a/common/legacy.php
+++ b/common/legacy.php
@@ -835,10 +835,10 @@ function handleError($errno, $errstr, $file, $line, $context)
 function getNumberingPath($no, $size = 3)
 {
 	$mod = pow(10, $size);
-	$output = sprintf('%0' . $size . 'd/', $no % $mod);
+	$output = sprintf('%0' . $size . 'd/', intval($no % $mod));
 	if($no >= $mod)
 	{
-		$output .= getNumberingPath((int)$no / $mod, $size);
+		$output .= getNumberingPath(intval($no / $mod), $size);
 	}
 	return $output;
 }