diff --git a/application/controllers/jobs/IssueResolver.php b/application/controllers/jobs/IssueResolver.php
index cf97b7f68..be66a6b23 100755
--- a/application/controllers/jobs/IssueResolver.php
+++ b/application/controllers/jobs/IssueResolver.php
@@ -45,6 +45,7 @@ class IssueResolver extends IssueResolver_Controller
 			'CORE_STUDENTSTATUS_0013' => 'CORE_STUDENTSTATUS_0013',
 			'CORE_STUDENTSTATUS_0014' => 'CORE_STUDENTSTATUS_0014',
 			'CORE_STUDENTSTATUS_0015' => 'CORE_STUDENTSTATUS_0015',
+			'CORE_STUDENTSTATUS_0016' => 'CORE_STUDENTSTATUS_0016',
 			'CORE_PERSON_0001' => 'CORE_PERSON_0001',
 			'CORE_PERSON_0002' => 'CORE_PERSON_0002',
 			'CORE_PERSON_0003' => 'CORE_PERSON_0003',
diff --git a/application/libraries/issues/PlausicheckDefinitionLib.php b/application/libraries/issues/PlausicheckDefinitionLib.php
index cef28a736..b44a5ce19 100644
--- a/application/libraries/issues/PlausicheckDefinitionLib.php
+++ b/application/libraries/issues/PlausicheckDefinitionLib.php
@@ -33,7 +33,8 @@ class PlausicheckDefinitionLib
 		'PrestudentMischformOhneOrgform' => 'PrestudentMischformOhneOrgform',
 		'StgPrestudentUngleichStgStudienplan' => 'StgPrestudentUngleichStgStudienplan',
 		'StgPrestudentUngleichStgStudent' => 'StgPrestudentUngleichStgStudent',
-		'StudentstatusNachAbbrecher' => 'StudentstatusNachAbbrecher'
+		'StudentstatusNachAbbrecher' => 'StudentstatusNachAbbrecher',
+		'DualesStudiumOhneMarkierung' => 'DualesStudiumOhneMarkierung'
 		//'StudienplanUngueltig' => 'StudienplanUngueltig'
 	);
 
diff --git a/application/libraries/issues/PlausicheckProducerLib.php b/application/libraries/issues/PlausicheckProducerLib.php
index c32f1f863..3a51e2b1e 100644
--- a/application/libraries/issues/PlausicheckProducerLib.php
+++ b/application/libraries/issues/PlausicheckProducerLib.php
@@ -12,8 +12,7 @@ class PlausicheckProducerLib
 
 	private $_ci; // ci instance
 	private $_extensionName; // name of extension
-	private $_app; // name of application
-	private $_konfiguration = array(); // konfigratio parameters
+	private $_konfiguration = array(); // configuration parameters
 
 	public function __construct($params = null)
 	{
diff --git a/application/libraries/issues/plausichecks/DualesStudiumOhneMarkierung.php b/application/libraries/issues/plausichecks/DualesStudiumOhneMarkierung.php
new file mode 100644
index 000000000..3951f6d76
--- /dev/null
+++ b/application/libraries/issues/plausichecks/DualesStudiumOhneMarkierung.php
@@ -0,0 +1,143 @@
+<?php
+
+if (! defined('BASEPATH')) exit('No direct script access allowed');
+
+require_once('PlausiChecker.php');
+
+/**
+ *
+ */
+class DualesStudiumOhneMarkierung extends PlausiChecker
+{
+	public function executePlausiCheck($params)
+	{
+		$results = array();
+
+		// get parameters from config
+		$exkludierte_studiengang_kz = isset($this->_config['exkludierteStudiengaenge']) ? $this->_config['exkludierteStudiengaenge'] : null;
+
+		// pass parameters needed for plausicheck
+		$studiensemester_kurzbz = isset($params['studiensemester_kurzbz']) ? $params['studiensemester_kurzbz'] : null;
+		$studiengang_kz = isset($params['studiengang_kz']) ? $params['studiengang_kz'] : null;
+
+		// get all students failing the plausicheck
+		$prestudentRes = $this->getDualesStudiumOhneMarkierung(
+			$studiensemester_kurzbz,
+			$studiengang_kz,
+			null,
+			$exkludierte_studiengang_kz
+		);
+
+		if (isError($prestudentRes)) return $prestudentRes;
+
+		if (hasData($prestudentRes))
+		{
+			$prestudents = getData($prestudentRes);
+
+			// populate results with data necessary for writing issues
+			foreach ($prestudents as $prestudent)
+			{
+				$results[] = array(
+					'person_id' => $prestudent->person_id,
+					'oe_kurzbz' => $prestudent->prestudent_stg_oe_kurzbz,
+					'fehlertext_params' => array(
+						'prestudent_id' => $prestudent->prestudent_id,
+						'studienplan' => $prestudent->studienplan
+					),
+					'resolution_params' => array(
+						'prestudent_id' => $prestudent->prestudent_id,
+						'studiensemester_kurzbz' => $prestudent->studiensemester_kurzbz
+					)
+				);
+			}
+		}
+
+		// return the results
+		return success($results);
+	}
+
+	/**
+	 * All prestudents in dual Studiengang should have set the dual flag to true.
+	 * @param studiensemester_kurzbz string check is to be executed for certain Studiensemester
+	 * @param studiengang_kz int if check is to be executed for certain Studiengang
+	 * @param prestudent_id int if check is to be executed only for one prestudent
+	 * @param exkludierte_studiengang_kz array if certain Studiengänge have to be excluded from check
+	 * @return success with prestudents or error
+	 */
+	public function getDualesStudiumOhneMarkierung(
+		$studiensemester_kurzbz,
+		$studiengang_kz = null,
+		$prestudent_id = null,
+		$exkludierte_studiengang_kz = null
+	) {
+		$params = array($studiensemester_kurzbz);
+
+		$qry = "
+			SELECT
+				DISTINCT pre.person_id, pre.prestudent_id,
+				stpl.bezeichnung AS studienplan,
+				status.studiensemester_kurzbz,
+				status.ausbildungssemester,
+				stg.oe_kurzbz AS prestudent_stg_oe_kurzbz
+			FROM
+				public.tbl_prestudent pre
+				JOIN public.tbl_prestudentstatus status USING(prestudent_id)
+				JOIN public.tbl_person USING(person_id)
+				JOIN lehre.tbl_studienplan stpl USING(studienplan_id)
+				JOIN public.tbl_studiengang stg ON pre.studiengang_kz = stg.studiengang_kz
+				JOIN public.tbl_studiensemester sem USING(studiensemester_kurzbz)
+			WHERE
+				(stpl.orgform_kurzbz = 'DUA' OR status.orgform_kurzbz = 'DUA')
+				AND pre.dual = FALSE
+				AND status.studiensemester_kurzbz=?
+				AND pre.bismelden
+				AND stg.melderelevant
+				AND NOT EXISTS (
+					SELECT 1
+					FROM
+						public.tbl_prestudentstatus
+						JOIN lehre.tbl_studienplan USING(studienplan_id)
+						JOIN public.tbl_studiensemester USING(studiensemester_kurzbz)
+					WHERE
+						prestudent_id = pre.prestudent_id
+						AND
+						(
+							-- if there is a newer non-dual status, dual has not to be set
+							(
+								(
+									tbl_studienplan.orgform_kurzbz <> stpl.orgform_kurzbz
+									OR status.orgform_kurzbz <> tbl_prestudentstatus.orgform_kurzbz
+								)
+								AND
+								(
+									tbl_studiensemester.ende::date > sem.ende::date
+									OR (tbl_studiensemester.ende::date = sem.ende::date AND tbl_prestudentstatus.datum::date > status.datum::date)
+								)
+							)
+							OR
+								-- exclude Abgewiesene - they are not reported
+								tbl_prestudentstatus.status_kurzbz = 'Abgewiesener'
+						)
+				)";
+
+		if (isset($studiengang_kz))
+		{
+			$qry .= " AND stg.studiengang_kz = ?";
+			$params[] = $studiengang_kz;
+		}
+
+		if (isset($prestudent_id))
+		{
+			$qry .= " AND pre.prestudent_id = ?";
+			$params[] = $prestudent_id;
+		}
+
+		if (isset($exkludierte_studiengang_kz) && !isEmptyArray($exkludierte_studiengang_kz))
+		{
+			$qry .= " AND stg.studiengang_kz NOT IN ?";
+			$params[] = $exkludierte_studiengang_kz;
+		}
+
+		return $this->_db->execReadOnlyQuery($qry, $params);
+	}
+}
diff --git a/application/libraries/issues/plausichecks/InaktiverStudentAktiverStatus.php b/application/libraries/issues/plausichecks/InaktiverStudentAktiverStatus.php
index dead2b1e7..59965e238 100644
--- a/application/libraries/issues/plausichecks/InaktiverStudentAktiverStatus.php
+++ b/application/libraries/issues/plausichecks/InaktiverStudentAktiverStatus.php
@@ -67,6 +67,7 @@ class InaktiverStudentAktiverStatus extends PlausiChecker
 		$prestudent_id = null,
 		$exkludierte_studiengang_kz = null
 	) {
+		$this->_ci->load->model('organisation/studiensemester_model', 'StudiensemesterModel');
 		$aktStudiensemesterRes = $this->_ci->StudiensemesterModel->getAkt();
 
 		if (isError($aktStudiensemesterRes)) return $aktStudiensemesterRes;
diff --git a/application/libraries/issues/resolvers/CORE_STUDENTSTATUS_0016.php b/application/libraries/issues/resolvers/CORE_STUDENTSTATUS_0016.php
new file mode 100644
index 000000000..0bba1ddff
--- /dev/null
+++ b/application/libraries/issues/resolvers/CORE_STUDENTSTATUS_0016.php
@@ -0,0 +1,36 @@
+<?php
+
+if (! defined('BASEPATH')) exit('No direct script access allowed');
+
+/**
+ * Student in dual Studiengang should have set the dual flag to true.
+ */
+class CORE_STUDENTSTATUS_0016 implements IIssueResolvedChecker
+{
+	public function checkIfIssueIsResolved($params)
+	{
+		if (!isset($params['prestudent_id']) || !is_numeric($params['prestudent_id']))
+			return error('Prestudent Id missing, issue_id: '.$params['issue_id']);
+
+		if (!isset($params['studiensemester_kurzbz']) || isEmptyString($params['studiensemester_kurzbz']))
+			return error('Studiensemester missing, issue_id: '.$params['issue_id']);
+
+		$this->_ci =& get_instance(); // get code igniter instance
+
+		$this->_ci->load->library('issues/plausichecks/DualesStudiumOhneMarkierung');
+
+		// check if issue persists
+		$checkRes = $this->_ci->dualesstudiumohnemarkierung->getDualesStudiumOhneMarkierung(
+			$params['studiensemester_kurzbz'],
+			null,
+			$params['prestudent_id']
+		);
+
+		if (isError($checkRes)) return $checkRes;
+
+		if (hasData($checkRes))
+			return success(false); // not resolved if issue is still present
+		else
+			return success(true); // resolved otherwise
+	}
+}
diff --git a/system/fehlerupdate.php b/system/fehlerupdate.php
index f29323c7c..89446982d 100644
--- a/system/fehlerupdate.php
+++ b/system/fehlerupdate.php
@@ -285,6 +285,14 @@ $fehlerArr = array(
 		'fehlertyp_kurzbz' => 'error',
 		'app' => 'core'
 	),
+	array(
+		'fehlercode' => 'CORE_STUDENTSTATUS_0016',
+		'fehler_kurzbz' => 'DualesStudiumOhneMarkierung',
+		'fehlercode_extern' => null,
+		'fehlertext' => 'StudentIn in dualem Studiengang nicht als dual markiert (prestudent_id %s, Studienplan %s)',
+		'fehlertyp_kurzbz' => 'error',
+		'app' => 'core'
+	),
 	array(
 		'fehlercode' => 'CORE_PERSON_0001',
 		'fehler_kurzbz' => 'GbDatumWeitZurueck',