diff --git a/php/modules/Album.php b/php/modules/Album.php
index 8c14aba..18e5191 100644
--- a/php/modules/Album.php
+++ b/php/modules/Album.php
@@ -28,7 +28,8 @@ class Album extends Module {
 
 	public function add($title = 'Untitled', $public = 0, $visible = 1) {
 
-		if (!isset($this->database)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -50,7 +51,8 @@ class Album extends Module {
 
 	public function get() {
 
-		if (!isset($this->database, $this->settings, $this->albumIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->settings, $this->albumIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -129,7 +131,8 @@ class Album extends Module {
 
 	public function getAll($public) {
 
-		if (!isset($this->database, $this->settings, $public)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->settings, $public));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -183,7 +186,8 @@ class Album extends Module {
 
 	private function getSmartInfo() {
 
-		if (!isset($this->database, $this->settings)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->settings));
 
 		# Unsorted
 		$unsorted	= $this->database->query("SELECT thumbUrl FROM lychee_photos WHERE album = 0 " . $this->settings['sorting']);
@@ -224,7 +228,8 @@ class Album extends Module {
 
 	public function getArchive() {
 
-		if (!isset($this->database, $this->albumIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->albumIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -326,7 +331,8 @@ class Album extends Module {
 
 	public function setTitle($title = 'Untitled') {
 
-		if (!isset($this->database, $this->albumIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->albumIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -347,7 +353,8 @@ class Album extends Module {
 
 	public function setDescription($description = '') {
 
-		if (!isset($this->database, $this->albumIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->albumIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -369,7 +376,8 @@ class Album extends Module {
 
 	public function getPublic() {
 
-		if (!isset($this->database, $this->albumIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->albumIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -390,7 +398,8 @@ class Album extends Module {
 
 	public function setPublic($password) {
 
-		if (!isset($this->database, $this->albumIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->albumIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -427,7 +436,8 @@ class Album extends Module {
 
 	public function setPassword($password) {
 
-		if (!isset($this->database, $this->albumIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->albumIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -445,7 +455,8 @@ class Album extends Module {
 
 	public function checkPassword($password) {
 
-		if (!isset($this->database, $this->albumIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->albumIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -465,7 +476,8 @@ class Album extends Module {
 
 	public function delete($albumIDs) {
 
-		if (!isset($this->database, $this->albumIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->albumIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
diff --git a/php/modules/Database.php b/php/modules/Database.php
index 0a5e94c..bfb9808 100755
--- a/php/modules/Database.php
+++ b/php/modules/Database.php
@@ -12,7 +12,8 @@ class Database extends Module {
 
 	static function connect($host = 'localhost', $user, $password, $name = 'lychee') {
 
-		if (!isset($host, $user, $password, $name)) return false;
+		# Check dependencies
+		Module::dependencies(isset($host, $user, $password, $name));
 
 		$database = new mysqli($host, $user, $password);
 
@@ -35,9 +36,10 @@ class Database extends Module {
 
 	}
 
-	static function update($database, $dbName, $version) {
+	static function update($database, $dbName, $version = 0) {
 
-		if (!isset($database)) return false;
+		# Check dependencies
+		Module::dependencies(isset($database, $dbName));
 
 		# List of updates
 		$updates = array(
@@ -63,7 +65,8 @@ class Database extends Module {
 
 	static function createConfig($host = 'localhost', $user, $password, $name = 'lychee') {
 
-		if (!isset($host, $user, $password, $name)) return false;
+		# Check dependencies
+		Module::dependencies(isset($host, $user, $password, $name));
 
 		$database = new mysqli($host, $user, $password);
 
@@ -99,7 +102,8 @@ if(!defined('LYCHEE')) exit('Error: Direct access is not allowed!');
 
 	static function createDatabase($database, $name = 'lychee') {
 
-		if (!isset($database, $name)) return false;
+		# Check dependencies
+		Module::dependencies(isset($database, $name));
 
 		# Create database
 		$result = $database->query("CREATE DATABASE IF NOT EXISTS $name;");
@@ -112,7 +116,8 @@ if(!defined('LYCHEE')) exit('Error: Direct access is not allowed!');
 
 	static function createTables($database) {
 
-		if (!isset($database)) return false;
+		# Check dependencies
+		Module::dependencies(isset($database));
 
 		# Create settings
 		if (!$database->query('SELECT * FROM lychee_settings LIMIT 0;')) {
diff --git a/php/modules/Module.php b/php/modules/Module.php
index dd08751..98e726d 100644
--- a/php/modules/Module.php
+++ b/php/modules/Module.php
@@ -26,4 +26,10 @@ class Module {
 
 	}
 
+	protected function dependencies($available = false) {
+
+		if ($available===false) exit('Error: Can not execute function. Missing parameters and variables.');
+
+	}
+
 }
\ No newline at end of file
diff --git a/php/modules/Photo.php b/php/modules/Photo.php
index bfd36ab..4a1616a 100755
--- a/php/modules/Photo.php
+++ b/php/modules/Photo.php
@@ -28,7 +28,8 @@ class Photo extends Module {
 
 	public function add($files, $albumID, $description = '', $tags = '') {
 
-		if (!isset($this->database)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -138,7 +139,8 @@ class Photo extends Module {
 
 	private function createThumb($url, $filename, $width = 200, $height = 200) {
 
-		if (!isset($this->settings, $url, $filename)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->settings, $url, $filename));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -223,7 +225,8 @@ class Photo extends Module {
 
 	private function adjustFile($path, $info) {
 
-		if (!isset($path, $info)) return false;
+		# Check dependencies
+		$this->dependencies(isset($path, $info));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -336,7 +339,8 @@ class Photo extends Module {
 
 	public function get($albumID) {
 
-		if (!isset($this->database, $this->photoIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->photoIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -376,7 +380,8 @@ class Photo extends Module {
 
 	private function getInfo($url) {
 
-		if (!isset($this->database, $url)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $url));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -469,7 +474,8 @@ class Photo extends Module {
 
 	public function getArchive() {
 
-		if (!isset($this->database, $this->photoIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->photoIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -501,7 +507,8 @@ class Photo extends Module {
 
 	function setTitle($title) {
 
-		if (!isset($this->database, $this->photoIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->photoIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -522,7 +529,8 @@ class Photo extends Module {
 
 	function setDescription($description) {
 
-		if (!isset($this->database, $this->photoIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->photoIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -544,7 +552,8 @@ class Photo extends Module {
 
 	public function setStar() {
 
-		if (!isset($this->database, $this->photoIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->photoIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -577,7 +586,8 @@ class Photo extends Module {
 
 	function getPublic($password) {
 
-		if (!isset($this->database, $this->photoIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->photoIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -604,7 +614,8 @@ class Photo extends Module {
 
 	public function setPublic() {
 
-		if (!isset($this->database, $this->photoIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->photoIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -629,7 +640,8 @@ class Photo extends Module {
 
 	function setAlbum($albumID) {
 
-		if (!isset($this->database, $this->photoIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->photoIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -647,7 +659,8 @@ class Photo extends Module {
 
 	public function setTags($tags) {
 
-		if (!isset($this->database, $this->photoIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->photoIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -670,7 +683,8 @@ class Photo extends Module {
 
 	public function delete() {
 
-		if (!isset($this->database, $this->photoIDs)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $this->photoIDs));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
diff --git a/php/modules/Session.php b/php/modules/Session.php
index c9db80f..211ea96 100755
--- a/php/modules/Session.php
+++ b/php/modules/Session.php
@@ -24,7 +24,8 @@ class Session extends Module {
 
 	public function init($database, $dbName, $public, $version) {
 
-		if (!isset($this->settings, $public, $version)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->settings, $public, $version));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
@@ -69,7 +70,8 @@ class Session extends Module {
 
 	public function login($username, $password) {
 
-		if (!isset($this->settings, $username, $password)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->settings, $username, $password));
 
 		# Call plugins
 		$this->plugins(__METHOD__, 0, func_get_args());
diff --git a/php/modules/Settings.php b/php/modules/Settings.php
index 2506e18..1c85057 100755
--- a/php/modules/Settings.php
+++ b/php/modules/Settings.php
@@ -23,7 +23,8 @@ class Settings extends Module {
 
 	public function get() {
 
-		if (!isset($this->database)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database));
 
 		# Execute query
 		$settings = $this->database->query('SELECT * FROM lychee_settings;');
@@ -40,7 +41,8 @@ class Settings extends Module {
 
 	public function setLogin($oldPassword = '', $username, $password) {
 
-		if (!isset($this->database)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database));
 
 		# Load settings
 		$settings = $this->get();
@@ -63,7 +65,8 @@ class Settings extends Module {
 
 	private function setUsername($username) {
 
-		if (!isset($this->database)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database));
 
 		# Parse
 		$username = htmlentities($username);
@@ -79,7 +82,8 @@ class Settings extends Module {
 
 	private function setPassword($password) {
 
-		if (!isset($this->database)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database));
 
 		if (strlen($password)<1||strlen($password)>50) return false;
 
@@ -93,7 +97,8 @@ class Settings extends Module {
 
 	public function setDropboxKey($key) {
 
-		if (!isset($this->database, $key)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $key));
 
 		if (strlen($key)<1||strlen($key)>50) return false;
 
@@ -107,7 +112,8 @@ class Settings extends Module {
 
 	public function setSorting($type, $order) {
 
-		if (!isset($this->database, $type, $order)) return false;
+		# Check dependencies
+		$this->dependencies(isset($this->database, $type, $order));
 
 		$sorting = 'ORDER BY ';