diff --git a/Classes/Common/DocumentAnnotation.php b/Classes/Common/DocumentAnnotation.php
index a3bcecb7f..d4ca9e829 100644
--- a/Classes/Common/DocumentAnnotation.php
+++ b/Classes/Common/DocumentAnnotation.php
@@ -77,38 +77,40 @@ function getAnnotations() {
 
                     if ($annotationTarget->getId()) {
                         if ($this->document->getCurrentDocument()->getFileLocation($annotationTarget->getId())) {
-                            if (
-                                $meiTargetPages = $this->getMeasurePagesByFileId(
-                                    $annotationTarget->getId(), $annotationTarget->getRangeValue()
-                                )
-                            ) {
-                                $targetPages[] = [
-                                    'target' => $annotationTarget,
-                                    'pages' => $meiTargetPages,
-                                    'verovioRelevant' => true
-                                ];
-
-                            } elseif (
-                                $audioTargetPages = $this->getAudioPagesByFileId(
-                                    $annotationTarget->getId(), $annotationTarget->getRangeValue()
-                                )
-                            ) {
-                                $targetPages[] = [
-                                    'target' => $annotationTarget,
-                                    'pages' => $audioTargetPages
-                                ];
-
-                            } elseif ($fileIdTargetPages = $this->getPagesByFileId($annotationTarget->getId())) {
-                                $targetPages[] = [
-                                    'target' => $annotationTarget,
-                                    'pages' => $fileIdTargetPages
-                                ];
-
-                            } else {
-                                $this->logger->warning(
-                                    ' No target pages found! Annotation: "' . $annotation->getId() . '", '
-                                    . 'Target: "' . $annotationTarget->getUrl() . '"'
-                                );
+                            if ($this->document->getCurrentDocument() instanceof MetsDocument) {
+                                if (
+                                    $meiTargetPages = $this->getMeasurePagesByFileId(
+                                        $annotationTarget->getId(), $annotationTarget->getRangeValue()
+                                    )
+                                ) {
+                                    $targetPages[] = [
+                                        'target' => $annotationTarget,
+                                        'pages' => $meiTargetPages,
+                                        'verovioRelevant' => true
+                                    ];
+
+                                } elseif (
+                                    $audioTargetPages = $this->getAudioPagesByFileId(
+                                        $annotationTarget->getId(), $annotationTarget->getRangeValue()
+                                    )
+                                ) {
+                                    $targetPages[] = [
+                                        'target' => $annotationTarget,
+                                        'pages' => $audioTargetPages
+                                    ];
+
+                                } elseif ($fileIdTargetPages = $this->getPagesByFileId($annotationTarget->getId())) {
+                                    $targetPages[] = [
+                                        'target' => $annotationTarget,
+                                        'pages' => $fileIdTargetPages
+                                    ];
+
+                                } else {
+                                    $this->logger->warning(
+                                        ' No target pages found! Annotation: "' . $annotation->getId() . '", '
+                                        . 'Target: "' . $annotationTarget->getUrl() . '"'
+                                    );
+                                }
                             }
                         } elseif ($logicalTargetPages = $this->getPagesByLogicalId($annotationTarget->getId())) {
                             $targetPages[] = [
@@ -322,6 +324,8 @@ protected function getMeasurePagesByFileId($fileId, $range = null)
         $measureIndex = 1;
         $startOrder = 0;
         $endOrder = 0;
+
+        // @phpstan-ignore-next-line It is ensured that getCurrentDocument returns a MetsDocument
         foreach ($this->document->getCurrentDocument()->musicalStructureInfo as $key => $musicalInfo) {
             if ($musicalInfo['type'] === 'measure' && is_array($musicalInfo['files'])) {
                 foreach ($musicalInfo['files'] as $file) {
@@ -368,6 +372,7 @@ protected function getMeasurePagesByFileId($fileId, $range = null)
         // Get the related page numbers
         $measurePages = [];
         foreach ($measures as $measure) {
+            // @phpstan-ignore-next-line It is ensured that getCurrentDocument returns a MetsDocument
             $measurePages[$measure['order']] = $this->document->getCurrentDocument()->musicalStructure[$measure['order']]['page'];
         }
 
@@ -405,7 +410,8 @@ protected static function loadData($document)
         $conf = GeneralUtility::makeInstance(ExtensionConfiguration::class)->get('dlf');
         $apiBaseUrl = $conf['annotationServerUrl'];
 
-        if ($apiBaseUrl) {
+        if ($apiBaseUrl && $document->getCurrentDocument() instanceof MetsDocument) {
+            // @phpstan-ignore-next-line It is ensured that getCurrentDocument returns a MetsDocument
             $purl = $document->getCurrentDocument()->mets->xpath('//mods:mods/mods:identifier[@type="purl"]');
             if (count($purl) > 0) {
                 $annotationRequest = new AnnotationRequest($apiBaseUrl);
diff --git a/Classes/Controller/NavigationController.php b/Classes/Controller/NavigationController.php
index 8099183c6..d95005b81 100644
--- a/Classes/Controller/NavigationController.php
+++ b/Classes/Controller/NavigationController.php
@@ -11,6 +11,7 @@
 
 namespace Kitodo\Dlf\Controller;
 
+use Kitodo\Dlf\Common\MetsDocument;
 use Kitodo\Dlf\Domain\Model\PageSelectForm;
 use TYPO3\CMS\Core\Utility\MathUtility;
 
@@ -116,24 +117,31 @@ public function mainAction(): void
         }
         $this->view->assign('features', $features);
 
-        if ($this->document->getCurrentDocument()->numMeasures > 0) {
-            $measureOptions = [];
-            $measurePages = [];
-            for ($i = 1; $i <= $this->document->getCurrentDocument()->numMeasures; $i++) {
-                $measureOptions[$i] = '[' . $i . ']' . ($this->document->getCurrentDocument()->musicalStructureInfo[$this->document->getCurrentDocument()->musicalStructure[$i]['measureid']]['orderlabel'] ? ' - ' . htmlspecialchars($this->document->getCurrentDocument()->musicalStructureInfo[$this->document->getCurrentDocument()->musicalStructureInfo[$i]]['orderlabel']) : '');
-                $measurePages[$i] = $this->document->getCurrentDocument()->musicalStructure[$i]['page'];
+        if ($this->document->getCurrentDocument() instanceof MetsDocument) {
+            // @phpstan-ignore-next-line It is ensured that getCurrentDocument returns a MetsDocument
+            if ($this->document->getCurrentDocument()->numMeasures > 0) {
+                $measureOptions = [];
+                $measurePages = [];
+                // @phpstan-ignore-next-line It is ensured that getCurrentDocument returns a MetsDocument
+                for ($i = 1; $i <= $this->document->getCurrentDocument()->numMeasures; $i++) {
+                    // @phpstan-ignore-next-line It is ensured that getCurrentDocument returns a MetsDocument
+                    $measureOptions[$i] = '[' . $i . ']' . ($this->document->getCurrentDocument()->musicalStructureInfo[$this->document->getCurrentDocument()->musicalStructure[$i]['measureid']]['orderlabel'] ? ' - ' . htmlspecialchars($this->document->getCurrentDocument()->musicalStructureInfo[$this->document->getCurrentDocument()->musicalStructureInfo[$i]]['orderlabel']) : '');
+                    // @phpstan-ignore-next-line It is ensured that getCurrentDocument returns a MetsDocument
+                    $measurePages[$i] = $this->document->getCurrentDocument()->musicalStructure[$i]['page'];
+                }
+
+                if (!isset($this->requestData['measure'])) {
+                    $currentMeasure = array_search($this->requestData['page'], $measurePages);
+                } else {
+                    $currentMeasure = $this->requestData['measure'];
+                }
+
+                $this->view->assign('currentMeasure', $currentMeasure);
+                // @phpstan-ignore-next-line It is ensured that getCurrentDocument returns a MetsDocument
+                $this->view->assign('numMeasures', $this->document->getCurrentDocument()->numMeasures);
+                $this->view->assign('measureOptions', $measureOptions);
+                $this->view->assign('measurePages', $measurePages);
             }
-
-            if (!isset($this->requestData['measure'])) {
-                $currentMeasure = array_search($this->requestData['page'], $measurePages);
-            } else {
-                $currentMeasure = $this->requestData['measure'];
-            }
-
-            $this->view->assign('currentMeasure', $currentMeasure);
-            $this->view->assign('numMeasures', $this->document->getCurrentDocument()->numMeasures);
-            $this->view->assign('measureOptions', $measureOptions);
-            $this->view->assign('measurePages', $measurePages);
         }
     }
 }
diff --git a/Classes/Controller/PageViewController.php b/Classes/Controller/PageViewController.php
index 3d2cb289a..f87c870b7 100644
--- a/Classes/Controller/PageViewController.php
+++ b/Classes/Controller/PageViewController.php
@@ -14,6 +14,8 @@
 use Kitodo\Dlf\Common\AbstractDocument;
 use Kitodo\Dlf\Common\DocumentAnnotation;
 use Kitodo\Dlf\Common\IiifManifest;
+use Kitodo\Dlf\Common\MetsDocument;
+use Kitodo\Dlf\Domain\Model\Document;
 use Kitodo\Dlf\Domain\Model\FormAddDocument;
 use TYPO3\CMS\Core\Utility\GeneralUtility;
 use TYPO3\CMS\Core\Utility\MathUtility;
@@ -127,9 +129,10 @@ public function mainAction(): void
             $this->fulltexts[1] = $this->getFulltext($this->requestData['page'] + 1);
             $this->annotationContainers[1] = $this->getAnnotationContainers($this->requestData['page'] + 1);
         }
-        $this->scores = $this->getScore($this->requestData['page']);
-
-        $this->measures = $this->getMeasures($this->requestData['page']);
+        if ($this->document->getCurrentDocument() instanceof MetsDocument) {
+            $this->scores = $this->getScore($this->requestData['page']);
+            $this->measures = $this->getMeasures($this->requestData['page']);
+        }
 
         // Get the controls for the map.
         $this->controls = explode(',', $this->settings['features']);
@@ -297,10 +300,11 @@ public function addDocumentAction(FormAddDocument $formAddDocument)
     /**
      * Get all measures from musical struct
      * @param int $page
-     * @param ?AbstractDocument $specificDoc
+     * @param ?Document $specificDoc
+     * @param int|null $docNumber
      * @return array
      */
-    protected function getMeasures(int $page, $specificDoc = null, $docNumber = null): array
+    protected function getMeasures(int $page, Document $specificDoc = null, $docNumber = null): array
     {
         if ($specificDoc) {
             $doc = $specificDoc;
@@ -313,6 +317,7 @@ protected function getMeasures(int $page, $specificDoc = null, $docNumber = null
         $measureLinks = [];
         $defaultFileId = $doc->physicalStructureInfo[$currentPhysId]['files']['DEFAULT'];
         if (isset($defaultFileId)) {
+            // @phpstan-ignore-next-line It is ensured that getCurrentDocument returns a MetsDocument
             $musicalStruct = $doc->musicalStructureInfo;
 
             $i = 0;
@@ -358,11 +363,11 @@ protected function getMeasures(int $page, $specificDoc = null, $docNumber = null
      * @access protected
      *
      * @param int $page: Page number
-     * @param ?MetsDocument $specificDoc
+     * @param ?Document $specificDoc
      *
      * @return array URL and MIME type of fulltext file
      */
-    protected function getScore(int $page, $specificDoc = null)
+    protected function getScore(int $page, Document $specificDoc = null)
     {
         $score = [];
         $loc = '';
@@ -385,6 +390,7 @@ protected function getScore(int $page, $specificDoc = null)
 
         if (!empty($loc)) {
             $score['mimetype'] = $doc->getFileMimeType($loc);
+            // @phpstan-ignore-next-line It is ensured that getCurrentDocument returns a MetsDocument
             $score['pagebeginning'] = $doc->getPageBeginning($pageId, $loc);
             $score['url'] = $doc->getFileLocation($loc);
             if ($this->settings['useInternalProxy']) {
@@ -602,11 +608,11 @@ protected function getAnnotationContainers(int $page): array
      *
      * @param int $page Page number
      *
-     * @param ?AbstractDocument $specificDoc
+     * @param ?Document $specificDoc
      *
      * @return array URL and MIME type of image file
      */
-    protected function getImage(int $page, $specificDoc = null): array
+    protected function getImage(int $page, Document $specificDoc = null): array
     {
         $image = [];
         // Get @USE value of METS fileGrp.