diff --git a/core/Documents/Install.class.php b/core/Documents/Install.class.php
index 583990d..45a5480 100644
--- a/core/Documents/Install.class.php
+++ b/core/Documents/Install.class.php
@@ -104,8 +104,8 @@ namespace Documents\Install {
       return NULL;
     }
 
-    private function composerUpdate(bool $dryRun = false): array {
-      $command = "composer update";
+    private function composerInstall(bool $dryRun = false): array {
+      $command = "composer install";
       if ($dryRun) {
         $command .= " --dry-run";
       }
@@ -127,8 +127,12 @@ namespace Documents\Install {
       return [$status, $output];
     }
 
-    private function getExternalDirectory(): string {
-      return implode(DIRECTORY_SEPARATOR, [WEBROOT, "core", "External"]);;
+    private function getExternalDirectory(bool $absolute = true): string {
+      if ($absolute) {
+        return implode(DIRECTORY_SEPARATOR, [WEBROOT, "core", "External"]);;
+      } else {
+        return implode(DIRECTORY_SEPARATOR, ["core", "External"]);
+      }
     }
 
     private function getCurrentStep(): int {
@@ -138,17 +142,16 @@ namespace Documents\Install {
       }
 
       $externalDir = $this->getExternalDirectory();
-      $vendorDir = $externalDir . DIRECTORY_SEPARATOR . "vendor";
-      if (!is_dir($vendorDir)) {
+      $autoload = implode(DIRECTORY_SEPARATOR, [$externalDir, "vendor", "autoload.php"]);
+      if (!is_file($autoload)) {
         return self::INSTALL_DEPENDENCIES;
       } else {
-        list ($status, $output) = $this->composerUpdate(true);
+        list ($status, $output) = $this->composerInstall(true);
         if ($status !== 0) {
-          $this->errorString = "Error executing 'composer update --dry-run'. Please verify that the command succeeds locally and then try again. Status Code: $status, Output: $output";
+          $this->errorString = "Error executing 'composer install --dry-run'. Please verify that the command succeeds locally and then try again. Status Code: $status, Output: $output";
           return self::CHECKING_REQUIREMENTS;
         } else {
-          if (!contains($output, "Nothing to modify in lock file")
-            || !contains($output, "Nothing to install, update or remove")) {
+          if (!contains($output, "Nothing to install, update or remove")) {
             return self::INSTALL_DEPENDENCIES;
           }
         }
@@ -219,17 +222,19 @@ namespace Documents\Install {
       $success = true;
       $failedRequirements = array();
 
-      $configDir = "core/Configuration/";
-      if (!is_writeable($configDir)) {
-        $failedRequirements[] = "<b>$configDir</b> is not writeable. Try running <b>chmod 700 $configDir</b>";
+      if (!is_writeable(WEBROOT)) {
+        $failedRequirements[] = sprintf("<b>%s</b> is not writeable. Try running <b>chmod 700 %s</b>", WEBROOT, WEBROOT);
         $success = false;
       }
 
       if (function_exists("posix_getuid")) {
         $userId = posix_getuid();
-        if (fileowner($configDir) !== $userId) {
+        if (fileowner(WEBROOT) !== $userId) {
           $username = posix_getpwuid($userId)['name'];
-          $failedRequirements[] = "<b>$configDir</b> is not owned by current user: $username ($userId). Try running <b>chown -R $username $configDir</b>";
+          $failedRequirements[] = sprintf("<b>%s</b> is not owned by current user: $username ($userId). " .
+              "Try running <b>chown -R $userId %s</b> or give the required directories write permissions: " .
+              "<b>core/Configuration</b>, <b>core/TemplateCache</b>, <b>core/External</b>",
+            WEBROOT, WEBROOT);
           $success = false;
         }
       }
@@ -259,7 +264,7 @@ namespace Documents\Install {
     }
 
     private function installDependencies(): array {
-      list ($status, $output) = $this->composerUpdate();
+      list ($status, $output) = $this->composerInstall();
       return ["success" => $status === 0, "msg" => $output];
     }
 
diff --git a/core/External/composer.lock b/core/External/composer.lock
index 3439192..7ecf941 100644
--- a/core/External/composer.lock
+++ b/core/External/composer.lock
@@ -527,30 +527,30 @@
         },
         {
             "name": "psr/log",
-            "version": "3.0.0",
+            "version": "1.1.4",
             "source": {
                 "type": "git",
                 "url": "https://github.com/php-fig/log.git",
-                "reference": "fe5ea303b0887d5caefd3d431c3e61ad47037001"
+                "reference": "d49695b909c3b7628b6289db5479a1c204601f11"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/php-fig/log/zipball/fe5ea303b0887d5caefd3d431c3e61ad47037001",
-                "reference": "fe5ea303b0887d5caefd3d431c3e61ad47037001",
+                "url": "https://api.github.com/repos/php-fig/log/zipball/d49695b909c3b7628b6289db5479a1c204601f11",
+                "reference": "d49695b909c3b7628b6289db5479a1c204601f11",
                 "shasum": ""
             },
             "require": {
-                "php": ">=8.0.0"
+                "php": ">=5.3.0"
             },
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "3.x-dev"
+                    "dev-master": "1.1.x-dev"
                 }
             },
             "autoload": {
                 "psr-4": {
-                    "Psr\\Log\\": "src"
+                    "Psr\\Log\\": "Psr/Log/"
                 }
             },
             "notification-url": "https://packagist.org/downloads/",
@@ -571,9 +571,9 @@
                 "psr-3"
             ],
             "support": {
-                "source": "https://github.com/php-fig/log/tree/3.0.0"
+                "source": "https://github.com/php-fig/log/tree/1.1.4"
             },
-            "time": "2021-07-14T16:46:02+00:00"
+            "time": "2021-05-03T11:20:27+00:00"
         },
         {
             "name": "spomky-labs/cbor-php",
diff --git a/core/core.php b/core/core.php
index 2c39fc4..c8c99e5 100644
--- a/core/core.php
+++ b/core/core.php
@@ -1,11 +1,11 @@
 <?php
 
-$vendorDir = implode(DIRECTORY_SEPARATOR, [__DIR__, "External", "vendor"]);
-if (is_dir($vendorDir)) {
-  require_once $vendorDir . DIRECTORY_SEPARATOR .  "autoload.php";
+$autoLoad = implode(DIRECTORY_SEPARATOR, [__DIR__, "External", "vendor", "autoload.php"]);
+if (is_file($autoLoad)) {
+  require_once $autoLoad;
 }
 
-define("WEBBASE_VERSION", "1.4.2");
+define("WEBBASE_VERSION", "1.4.3");
 
 spl_autoload_extensions(".php");
 spl_autoload_register(function($class) {
diff --git a/docker/php/Dockerfile b/docker/php/Dockerfile
index 22710a9..cca781e 100644
--- a/docker/php/Dockerfile
+++ b/docker/php/Dockerfile
@@ -1,6 +1,11 @@
-FROM php:7-fpm
+FROM composer:latest AS composer
+FROM php:7.4-fpm
 WORKDIR "/application"
 RUN mkdir -p /application/core/Configuration
 RUN chown -R www-data:www-data /application
-RUN docker-php-ext-install mysqli
+RUN apt-get update -y && apt-get install libyaml-dev libzip-dev -y && apt-get clean && \
+    pecl install yaml && echo "extension=yaml.so" > /usr/local/etc/php/conf.d/ext-yaml.ini && \
+    docker-php-ext-enable yaml
+RUN docker-php-ext-install mysqli zip
+COPY --from=composer /usr/bin/composer /usr/bin/composer
 USER www-data
\ No newline at end of file