diff --git a/dta.zip b/dta.zip
index 8e1804094b0480d23171076450aa15013eda0460..3a03fb56fd9988ad9f00e20fa842f77e9cc4e0c9 100644
Binary files a/dta.zip and b/dta.zip differ
diff --git a/dta/classes/privacy/provider.php b/dta/classes/privacy/provider.php
index d67682710b449c466d30c544b5178660d9d0df12..fcbe94944d7e07e1eae9c4b01bb7fce31c9e7370 100644
--- a/dta/classes/privacy/provider.php
+++ b/dta/classes/privacy/provider.php
@@ -16,11 +16,6 @@
 
 namespace assignsubmission_dta\privacy;
 
-use core_privacy\local\metadata\collection;
-use core_privacy\local\request\writer;
-use core_privacy\local\request\contextlist;
-use mod_assign\privacy\assign_plugin_request_data;
-
 /**
  * provider for data privacy
  *
@@ -28,6 +23,11 @@ use mod_assign\privacy\assign_plugin_request_data;
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @copyright Gero Lueckemeyer and student project teams
  */
+use core_privacy\local\metadata\collection;
+use core_privacy\local\request\writer;
+use core_privacy\local\request\contextlist;
+use mod_assign\privacy\assign_plugin_request_data;
+
 class provider implements \core_privacy\local\metadata\provider,
         \mod_assign\privacy\assignsubmission_provider,
         \mod_assign\privacy\assignsubmission_user_provider {
@@ -39,9 +39,9 @@ class provider implements \core_privacy\local\metadata\provider,
 
     /**
      * This is the metadata information for the assignsubmission_dta plugin.
-     * @param stdClass $collection the collection of metadata filled by the plugin
+     * @param collection $collection the collection of metadata filled by the plugin
      */
-    public static function get_metadata(stdClass $collection): collection {
+    public static function get_metadata(collection $collection): collection {
         $collection->add_subsystem_link(
             'core_files',
             [],
diff --git a/dta/lib.php b/dta/lib.php
index 7f24d41f5b50b987dab7e080ea2c5b172ed04378..c090bfc9e6b6524bbb50867fdc2d5e9b6e568103 100644
--- a/dta/lib.php
+++ b/dta/lib.php
@@ -37,9 +37,9 @@ function assignsubmission_dta_pluginfile(
     $course,
     $cm,
     context $context,
-    string $filearea,
+    $filearea,
     $args,
-    bool $forcedownload
+    $forcedownload
     ) {
     global $DB, $CFG;
 
diff --git a/dta/locallib.php b/dta/locallib.php
index fa9e0f9fd642d83528305599253ae6e2fc607f33..e3ad8e0ac514b48706999179a9385abd60502d97 100644
--- a/dta/locallib.php
+++ b/dta/locallib.php
@@ -226,7 +226,7 @@ class assign_submission_dta extends assign_submission_plugin {
      *
      * @param int $submissionid submission id to check
      * @param string $areaid filearea id to count
-     * @return int
+     * @return int number of files submitted in the filearea
      */
     private function count_files(int $submissionid, string $areaid) {
         $fs = get_file_storage();
diff --git a/dta/models/DtaResult.php b/dta/models/DtaResult.php
index 592d6f0633bfeec9bdb4024e2d0b845be4ab5f94..bd7d4b0842ac26d8a94145426fcb096c0014b0ce 100644
--- a/dta/models/DtaResult.php
+++ b/dta/models/DtaResult.php
@@ -143,9 +143,9 @@ class DtaResultSummary {
     /**
      * Decodes the JSON result summary returned by the backend service call into the plugin PHP data structure.
      * @param string $jsonstring jsonString containing DtaResultSummary
-     * @return DtaResultSummary
+     * @return DtaResultSummary the result summary
      */
-    public static function decodejson($jsonstring): DtaResultSummary {
+    public static function decodejson(string $jsonstring): DtaResultSummary {
         $response = json_decode($jsonstring);
 
         $summary = new DtaResultSummary();
@@ -188,6 +188,7 @@ class DtaResultSummary {
         return $ret;
     }
 
+
     /**
      * Returns the number of detail results attached to the summary.
      * @return int count of occurences
diff --git a/dta/utils/backend.php b/dta/utils/backend.php
index fc5fd83a41e1f056f66ddfc99486e8bd167e1d5b..a881f9ff32548dfba4bff5655fde61bc109fb781 100644
--- a/dta/utils/backend.php
+++ b/dta/utils/backend.php
@@ -14,6 +14,14 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
+/**
+ * This file contains the backend webservice contact functionality for the DTA plugin
+ *
+ * @package    assignsubmission_dta
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @copyright Gero Lueckemeyer and student project teams
+ */
+
 /**
  * backend webservice contact utility class
  *
@@ -40,11 +48,11 @@ class DtaBackendUtils {
     /**
      * Sends the configuration textfile uploaded by prof to the backend.
      *
-     * @param stdClass $assignment assignment this test-config belongs to
-     * @param stdClass $file uploaded test-config
+     * @param $assignment assignment this test-config belongs to
+     * @param $file uploaded test-config
      * @return bool true if no error occurred
      */
-    public static function sendtestconfigtobackend(stdClass $assignment, $file): bool {
+    public static function sendtestconfigtobackend($assignment, $file): bool {
         $backendaddress = self::getbackendbaseurl();
         if (empty($backendaddress)) {
             return true;
@@ -70,11 +78,11 @@ class DtaBackendUtils {
     /**
      * Sends sumbission config or archive to backend to be tested.
      *
-     * @param stdClass $assignment assignment this submission is done for
-     * @param stdClass $file submission config file or archive with submission
+     * @param $assignment assignment this submission is done for
+     * @param $file submission config file or archive with submission
      * @return string json string with testresults or null on error
      */
-    public static function sendsubmissiontobackend(stdClass $assignment, $file): ?string {
+    public static function sendsubmissiontobackend($assignment, $file): ?string {
         $backendaddress = self::getbackendbaseurl();
         if (empty($backendaddress)) {
             return true;
diff --git a/dta/utils/database.php b/dta/utils/database.php
index e9aae8333e9ff38d0234787c84942f2cb8d76cd8..8d54c0607fc2b1c56b807cb410689d1fb096ecc7 100644
--- a/dta/utils/database.php
+++ b/dta/utils/database.php
@@ -14,14 +14,6 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-/**
- * persistence layer utility class
- *
- * @package assignsubmission_dta
- * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
- * @copyright Gero Lueckemeyer and student project teams
- */
-
 /**
  * persistence layer utility class
  *
@@ -45,7 +37,7 @@ class DbUtils {
      *
      * @param int $assignmentid assignment id to search for
      * @param int $submissionid submission id to search for
-     * @return DtaResultSummary representing given submission
+     * @return DttResultSummary representing given submission
      */
     public static function getresultsummaryfromdatabase(
         int $assignmentid,
@@ -96,9 +88,9 @@ class DbUtils {
      * save given result summary and single results to database
      * under given assignment and submission id
      *
-     * @param int $assignmentid assigment this is submission is linked to
-     * @param int $submissionid submission of this result
-     * @param DtaResultSummary $summary instance to persist
+     * @param $assignmentid assigment this is submission is linked to
+     * @param $submissionid submission of this result
+     * @param $summary instance to persist
      */
     public static function storeresultsummarytodatabase(
         int $assignmentid,
diff --git a/dta/utils/view.php b/dta/utils/view.php
index 41409daf3768d8326090b2b3a1c91d624d56c946..ebd223a3c6b4df92cfee2b9f57a6ca956fc2e0e2 100644
--- a/dta/utils/view.php
+++ b/dta/utils/view.php
@@ -31,8 +31,8 @@ class view_submission_utils {
     /**
      * generates a short summary html
      *
-     * @param int $assignmentid id of the assignment
-     * @param int $submissionid id of the submission for which to create a report
+     * @param $assignmentid assignment
+     * @param $submissionid submission to create a report for
      * @return string html
      */
     public static function generatesummaryhtml(
@@ -87,8 +87,8 @@ class view_submission_utils {
     /**
      * generates detailed view html
      *
-     * @param int $assignmentid id of the assignment
-     * @param int $submissionid id of the submission for which to create a report
+     * @param $assignmentid assignment
+     * @param $submissionid submission to create a report for
      */
     public static function generatedetailhtml(
         int $assignmentid,
diff --git a/dta/version.php b/dta/version.php
index c1d02a029ae402daa95c32134420f8bf95e881a3..65508747ee400b4b1a9aab338bc4ac57608e7253 100644
--- a/dta/version.php
+++ b/dta/version.php
@@ -25,7 +25,7 @@
 defined('MOODLE_INTERNAL') || die();
 
 $plugin->version   = 3000000;
-$plugin->requires  = 2020061525; // Moodle 3.9 LTS. Will likely run with unsupported older versions of the 3.x branch.
+$plugin->requires  = 2020061525; // Moodle 3.9 LTS. Older unsupported versions from the 3.x branch should also work.
 $plugin->component = 'assignsubmission_dta';
 $plugin->maturity  = MATURITY_STABLE;
 $plugin->release   = "3.0.0";