diff --git a/Neos.ContentRepository/Classes/Domain/Model/Node.php b/Neos.ContentRepository/Classes/Domain/Model/Node.php
index 551a73c273d..d5d64d6a0ac 100644
--- a/Neos.ContentRepository/Classes/Domain/Model/Node.php
+++ b/Neos.ContentRepository/Classes/Domain/Model/Node.php
@@ -1663,7 +1663,40 @@ protected function createRecursiveCopy(NodeInterface $referenceNode, string $nod
         $referenceNodeDimensionsHash = Utility::sortDimensionValueArrayAndReturnDimensionsHash($referenceNodeDimensions);
         $thisDimensions = $this->getDimensions();
         $thisNodeDimensionsHash = Utility::sortDimensionValueArrayAndReturnDimensionsHash($thisDimensions);
-        if ($detachedCopy === false && $referenceNodeDimensionsHash !== $thisNodeDimensionsHash && $referenceNode->getContext()->getNodeByIdentifier($this->getIdentifier()) === null) {
+
+        // We are only allowed to re-use the node's identifier if the copy-target's context (from $referenceNode)
+        // does NOT contain this identifier.
+        // We need to check this also taking removed and invisible nodes into account.
+        //
+        // Without changing the context, removedContentShown is typically FALSE, leading to the FOLLOWING BUG:
+        //
+        // PREREQUISITES:
+        // - a language dimension with two values, without fallbacks ("de" and "en")
+        // - create a page in DE with content nodes "text1" and "text2"
+        // - translate this page to EN and let it copy all content. "text1" also exists on EN now, and has the same identifier as in DE.
+        // - publish everything.
+        //
+        // REPRODUCING THE BUG: (comment out the removedContentShown line below)
+        // - select "text1" in "DE" and copy it
+        // - switch to EN
+        // - REMOVE the node "text1" in EN
+        // - PASTE the node from the clipboard AFTER text2 (in EN).
+        // - (this triggers the code we have here.)
+        //
+        // EXPECTED BEHAVIOR
+        // - the pasted node is shown
+        //
+        // ACTUAL BEHAVIOR
+        // - the pasted node is not shown, but is still in the database.
+        // - it can happen that the node *is* shown, if it is inserted above the removed node. Still, we have an invariant violation nevertheless.
+        // - this can also trigger problems when **publishing** the not-rendered-anymore-node (UniqueConstraint errors in the database) - this is
+        //   how we actually found the error.
+        $contextPropertiesWithAllNodesShown = $referenceNode->getContext()->getProperties();
+        $contextPropertiesWithAllNodesShown['invisibleContentShown'] = true;
+        $contextPropertiesWithAllNodesShown['removedContentShown'] = true;
+        $contextPropertiesWithAllNodesShown['inaccessibleContentShown'] = true;
+        $referenceNodeContextWithAllNodesShown = $this->contextFactory->create($contextPropertiesWithAllNodesShown);
+        if ($detachedCopy === false && $referenceNodeDimensionsHash !== $thisNodeDimensionsHash && $referenceNodeContextWithAllNodesShown->getNodeByIdentifier($this->getIdentifier()) === null) {
             // If the target dimensions are different than this one, and there is no node shadowing this one in the target dimension yet, we use the same
             // node identifier, effectively creating a new node variant.
             $identifier = $this->getIdentifier();
diff --git a/Neos.ContentRepository/Tests/Functional/Domain/CopyNodeAcrossDimensionsBug3265Test.php b/Neos.ContentRepository/Tests/Functional/Domain/CopyNodeAcrossDimensionsBug3265Test.php
new file mode 100644
index 00000000000..c3946eee463
--- /dev/null
+++ b/Neos.ContentRepository/Tests/Functional/Domain/CopyNodeAcrossDimensionsBug3265Test.php
@@ -0,0 +1,223 @@
+<?php
+namespace Neos\ContentRepository\Tests\Functional\Domain;
+
+/*
+ * This file is part of the Neos.ContentRepository package.
+ *
+ * (c) Contributors of the Neos Project - www.neos.io
+ *
+ * This package is Open Source Software. For the full copyright and license
+ * information, please view the LICENSE file which was distributed with this
+ * source code.
+ */
+
+use Neos\Flow\Configuration\ConfigurationManager;
+use Neos\Flow\Tests\FunctionalTestCase;
+use Neos\ContentRepository\Domain\Factory\NodeFactory;
+use Neos\ContentRepository\Domain\Model\Workspace;
+use Neos\ContentRepository\Domain\Repository\ContentDimensionRepository;
+use Neos\ContentRepository\Domain\Repository\NodeDataRepository;
+use Neos\ContentRepository\Domain\Repository\WorkspaceRepository;
+use Neos\ContentRepository\Domain\Service\Context;
+use Neos\ContentRepository\Domain\Service\ContextFactoryInterface;
+use Neos\ContentRepository\Domain\Service\NodeTypeManager;
+
+/**
+ * Functional test case which covers https://github.com/neos/neos-development-collection/issues/3265
+ */
+class CopyNodeAcrossDimensionsBug3265Test extends FunctionalTestCase
+{
+    /**
+     * @var Context
+     */
+    protected $liveContextDe;
+
+    /**
+     * @var Context
+     */
+    protected $liveContextEn;
+
+    /**
+     * @var Context
+     */
+    protected $userWorkspaceContextDe;
+
+    /**
+     * @var Context
+     */
+    protected $userWorkspaceContextEn;
+
+    /**
+     * @var boolean
+     */
+    protected static $testablePersistenceEnabled = true;
+
+    /**
+     * @var NodeDataRepository
+     */
+    protected $nodeDataRepository;
+
+    /**
+     * @var WorkspaceRepository
+     */
+    protected $workspaceRepository;
+
+    /**
+     * @var Workspace
+     */
+    protected $liveWorkspace;
+
+    /**
+     * @var ContextFactoryInterface
+     */
+    protected $contextFactory;
+
+    /**
+     * @var NodeTypeManager
+     */
+    protected $nodeTypeManager;
+
+    /**
+     * @var ContentDimensionRepository
+     */
+    protected $contentDimensionRepository;
+
+    /**
+     * @return void
+     */
+    public function setUp(): void
+    {
+        parent::setUp();
+        $this->persistAndResetStateCompletely();
+    }
+
+    /**
+     * @return void
+     */
+    public function tearDown(): void
+    {
+        parent::tearDown();
+        $this->inject($this->contextFactory, 'contextInstances', []);
+        $configuredDimensions = $this->objectManager->get(ConfigurationManager::class)->getConfiguration(ConfigurationManager::CONFIGURATION_TYPE_SETTINGS, 'Neos.ContentRepository.contentDimensions');
+        $this->contentDimensionRepository->setDimensionsConfiguration($configuredDimensions);
+    }
+
+    /**
+     * @test
+     */
+    public function testForBug3265()
+    {
+        // FIXTURE SETUP
+        // node1 in DE and EN (live)
+        // node2 in DE and EN (live)
+        $this->liveContextDe->getRootNode()->createNode('node1', null, 'node1-identifier');
+        $this->liveContextDe->getRootNode()->createNode('node2', null, 'node2-identifier');
+        $this->liveContextEn->getRootNode()->createNode('node1', null, 'node1-identifier');
+        $this->liveContextEn->getRootNode()->createNode('node2', null, 'node2-identifier');
+        $this->persistAndResetStateCompletely();
+
+        // REPRODUCING THE PROBLEM
+        // 1) we remove the node1 in DE (in user workspace)
+        $this->userWorkspaceContextDe->getRootNode()->getNode('node1')->remove();
+        $this->persistAndResetStateCompletely();
+
+        // 2) we copy the node1 from EN to DE after node2 (in user workspace)
+        $enNode1 = $this->userWorkspaceContextEn->getRootNode()->getNode('node1');
+        $deNode2 = $this->userWorkspaceContextDe->getRootNode()->getNode('node2');
+        $this->assertNotNull($enNode1, 'enNode1 must not be null');
+        $this->assertNotNull($deNode2, 'deNode2 must not be null');
+        $enNode1->copyAfter($deNode2, 'node-1-pasted');
+        $this->persistAndResetStateCompletely();
+
+        // EXPECTATION / ASSERTION
+        // the copied node must appear underneath the root
+        $childNodes = $this->userWorkspaceContextDe->getRootNode()->getChildNodes();
+        $childNodePaths = [];
+        foreach ($childNodes as $node) {
+            $childNodePaths[] = $node->getPath();
+        }
+        $expected = ['/node2', '/node-1-pasted'];
+        $this->assertEquals($expected, $childNodePaths, 'We copied node-1-pasted, but it does not appear');
+    }
+
+    protected function persistAndResetStateCompletely()
+    {
+        if ($this->nodeDataRepository !== null) {
+            $this->nodeDataRepository->flushNodeRegistry();
+        }
+        /** @var NodeFactory $nodeFactory */
+        $nodeFactory = $this->objectManager->get(NodeFactory::class);
+        $nodeFactory->reset();
+        $this->contextFactory = $this->objectManager->get(ContextFactoryInterface::class);
+        $this->contextFactory->reset();
+        $this->persistenceManager->persistAll();
+        $this->persistenceManager->clearState();
+        $this->nodeDataRepository = null;
+        $this->rootNode = null;
+
+        $this->nodeDataRepository = new NodeDataRepository();
+
+        if ($this->liveWorkspace === null) {
+            $this->liveWorkspace = new Workspace('live');
+            $this->objectManager->get(WorkspaceRepository::class);
+            $this->workspaceRepository = $this->objectManager->get(WorkspaceRepository::class);
+            $this->workspaceRepository->add($this->liveWorkspace);
+            $this->workspaceRepository->add(new Workspace('user-admin', $this->liveWorkspace));
+            $this->persistenceManager->persistAll();
+        }
+
+
+        $this->liveContextDe = $this->contextFactory->create([
+            'workspaceName' => 'live',
+            'dimensions' => [
+                'language' => ['de']
+            ],
+            'targetDimensions' => [
+                'language' => 'de'
+            ]
+        ]);
+        $this->liveContextEn = $this->contextFactory->create([
+            'workspaceName' => 'live',
+            'dimensions' => [
+                'language' => ['en']
+            ],
+            'targetDimensions' => [
+                'language' => 'en'
+            ]
+        ]);
+        $this->userWorkspaceContextDe = $this->contextFactory->create([
+            'workspaceName' => 'user-admin',
+            'dimensions' => [
+                'language' => ['de']
+            ],
+            'targetDimensions' => [
+                'language' => 'de'
+            ]
+        ]);
+        $this->userWorkspaceContextEn = $this->contextFactory->create([
+            'workspaceName' => 'user-admin',
+            'dimensions' => [
+                'language' => ['en']
+            ],
+            'targetDimensions' => [
+                'language' => 'en'
+            ]
+        ]);
+        $this->nodeTypeManager = $this->objectManager->get(NodeTypeManager::class);
+        $this->contentDimensionRepository = $this->objectManager->get(ContentDimensionRepository::class);
+
+        $this->contentDimensionRepository->setDimensionsConfiguration([
+            'language' => [
+                'default' => 'en',
+                'presets' => [
+                    'enPreset' => [
+                        'values' => ['en']
+                    ],
+                    'dePreset' => [
+                        'values' => ['de']
+                    ]
+                ]
+            ]
+        ]);
+    }
+}
diff --git a/Neos.Media.Browser/Resources/Private/Templates/Asset/Index.html b/Neos.Media.Browser/Resources/Private/Templates/Asset/Index.html
index 2da276470c0..e4d06ff0e35 100644
--- a/Neos.Media.Browser/Resources/Private/Templates/Asset/Index.html
+++ b/Neos.Media.Browser/Resources/Private/Templates/Asset/Index.html
@@ -319,10 +319,11 @@ <h2>{neos:backend.translate(id: 'connectionError', package: 'Neos.Media.Browser'
     <script type="text/javascript">
         var uploadUrl = "{f:uri.action(action: 'upload', addQueryString: true, additionalParams: {__csrfToken: '{f:security.csrfToken()}'}, absolute: true) -> f:format.raw()}";
         var maximumFileUploadSize = {maximumFileUploadSize};
-
+<![CDATA[
         if (window.parent !== window && window.parent.NeosMediaBrowserCallbacks && window.parent.NeosMediaBrowserCallbacks.refreshThumbnail) {
             window.parent.NeosMediaBrowserCallbacks.refreshThumbnail();
         }
+]]>
     </script>
     <f:form action="tagAsset" addQueryString="true" id="tag-asset-form" format="json">
         <f:form.hidden name="asset[__identity]" id="tag-asset-form-asset" />
diff --git a/Neos.Neos/Classes/Fusion/DimensionsMenuItemsImplementation.php b/Neos.Neos/Classes/Fusion/DimensionsMenuItemsImplementation.php
index 2511b2c2f3e..6b0b0647145 100644
--- a/Neos.Neos/Classes/Fusion/DimensionsMenuItemsImplementation.php
+++ b/Neos.Neos/Classes/Fusion/DimensionsMenuItemsImplementation.php
@@ -174,6 +174,10 @@ protected function itemLabel(string $pinnedDimensionName = null, NodeInterface $
      */
     protected function getNodeInDimensions(array $dimensions, array $targetDimensions)
     {
+        if ($this->currentNode === null) {
+            return null;
+        }
+
         $q = new FlowQuery([$this->currentNode]);
 
         return $q->context([
diff --git a/Neos.Neos/Documentation/Appendixes/ReleaseNotes/520.rst b/Neos.Neos/Documentation/Appendixes/ReleaseNotes/520.rst
index faf2c164a35..0ded2d407b2 100644
--- a/Neos.Neos/Documentation/Appendixes/ReleaseNotes/520.rst
+++ b/Neos.Neos/Documentation/Appendixes/ReleaseNotes/520.rst
@@ -6,7 +6,6 @@ This is a planned feature release and includes the following new feature as well
 
 Update procedure includes updating dependencies and running `./flow doctrine:migrate` as for  most updates.
 
-================
 What has changed
 ================
 
diff --git a/Neos.Neos/Resources/Private/Fusion/Prototypes/ImageUri.fusion b/Neos.Neos/Resources/Private/Fusion/Prototypes/ImageUri.fusion
index b021c80c707..28de2b0e192 100644
--- a/Neos.Neos/Resources/Private/Fusion/Prototypes/ImageUri.fusion
+++ b/Neos.Neos/Resources/Private/Fusion/Prototypes/ImageUri.fusion
@@ -39,6 +39,7 @@ prototype(Neos.Neos:ImageTag) < prototype(Neos.Fusion:Tag) {
 
 	tagName = 'img'
 	attributes {
+		alt = ''
 		src = Neos.Neos:ImageUri {
 			asset = ${asset}
 			width = ${width}