Try to delete the cypress folder of the viewer app

lib/composer/composer/autoload_classmap.php

@@ -1065,6 +1065,7 @@
     'OC\\Repair\\NC15\\SetVcardDatabaseUID' => $baseDir . '/lib/private/Repair/NC15/SetVcardDatabaseUID.php',
     'OC\\Repair\\NC16\\AddClenupLoginFlowV2BackgroundJob' => $baseDir . '/lib/private/Repair/NC16/AddClenupLoginFlowV2BackgroundJob.php',
     'OC\\Repair\\NC16\\CleanupCardDAVPhotoCache' => $baseDir . '/lib/private/Repair/NC16/CleanupCardDAVPhotoCache.php',
+    'OC\\Repair\\NC16\\RemoveCypressFiles' => $baseDir . '/lib/private/Repair/NC16/RemoveCypressFiles.php',
     'OC\\Repair\\OldGroupMembershipShares' => $baseDir . '/lib/private/Repair/OldGroupMembershipShares.php',
     'OC\\Repair\\Owncloud\\DropAccountTermsTable' => $baseDir . '/lib/private/Repair/Owncloud/DropAccountTermsTable.php',
     'OC\\Repair\\Owncloud\\SaveAccountsTableData' => $baseDir . '/lib/private/Repair/Owncloud/SaveAccountsTableData.php',

lib/composer/composer/autoload_static.php

@@ -1099,6 +1099,7 @@ class ComposerStaticInit53792487c5a8370acc0b06b1a864ff4c
         'OC\\Repair\\NC15\\SetVcardDatabaseUID' => __DIR__ . '/../../..' . '/lib/private/Repair/NC15/SetVcardDatabaseUID.php',
         'OC\\Repair\\NC16\\AddClenupLoginFlowV2BackgroundJob' => __DIR__ . '/../../..' . '/lib/private/Repair/NC16/AddClenupLoginFlowV2BackgroundJob.php',
         'OC\\Repair\\NC16\\CleanupCardDAVPhotoCache' => __DIR__ . '/../../..' . '/lib/private/Repair/NC16/CleanupCardDAVPhotoCache.php',
+        'OC\\Repair\\NC16\\RemoveCypressFiles' => __DIR__ . '/../../..' . '/lib/private/Repair/NC16/RemoveCypressFiles.php',
         'OC\\Repair\\OldGroupMembershipShares' => __DIR__ . '/../../..' . '/lib/private/Repair/OldGroupMembershipShares.php',
         'OC\\Repair\\Owncloud\\DropAccountTermsTable' => __DIR__ . '/../../..' . '/lib/private/Repair/Owncloud/DropAccountTermsTable.php',
         'OC\\Repair\\Owncloud\\SaveAccountsTableData' => __DIR__ . '/../../..' . '/lib/private/Repair/Owncloud/SaveAccountsTableData.php',

lib/private/Repair.php

@@ -45,6 +45,7 @@
 use OC\Repair\NC15\SetVcardDatabaseUID;
 use OC\Repair\NC16\AddClenupLoginFlowV2BackgroundJob;
 use OC\Repair\NC16\CleanupCardDAVPhotoCache;
+use OC\Repair\NC16\RemoveCypressFiles;
 use OC\Repair\OldGroupMembershipShares;
 use OC\Repair\Owncloud\DropAccountTermsTable;
 use OC\Repair\Owncloud\SaveAccountsTableData;
@@ -155,6 +156,7 @@ public static function getRepairSteps() {
 			new CleanupCardDAVPhotoCache(\OC::$server->getConfig(), \OC::$server->getAppDataDir('dav-photocache'), \OC::$server->getLogger()),
 			new AddClenupLoginFlowV2BackgroundJob(\OC::$server->getJobList()),
 			new RemoveLinkShares(\OC::$server->getDatabaseConnection(), \OC::$server->getConfig(), \OC::$server->getGroupManager(), \OC::$server->getNotificationManager(), \OC::$server->query(ITimeFactory::class)),
+			\OC::$server->query(RemoveCypressFiles::class),
 		];
 	}
 

lib/private/Repair/NC16/RemoveCypressFiles.php

@@ -0,0 +1,82 @@
+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2019, Morris Jobke <hey@morrisjobke.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\Repair\NC16;
+
+use OC\IntegrityCheck\Checker;
+use OCP\Migration\IOutput;
+use OCP\Migration\IRepairStep;
+
+/**
+ * Class CleanupCypressFiles
+ *
+ * This repair step removes "cypress" files and folder created by viewer app in 16.0.1
+ *
+ * See https://github.com/nextcloud/server/issues/16229 for more details.
+ *
+ * @deprecated - can be removed in 18 because this is the first version where no migration from 16 can happen
+ */
+class RemoveCypressFiles implements IRepairStep {
+
+	/** @var Checker $checker */
+	private $checker;
+
+	private $pathToViewerApp = __DIR__ . '/../../../../apps/viewer';
+
+	public function getName(): string {
+		return 'Cleanup cypress files from viewer app';
+	}
+
+	public function __construct(Checker $checker) {
+		$this->checker = $checker;
+	}
+
+	public function run(IOutput $output): void {
+		$file = $this->pathToViewerApp . '/cypress.json';
+		if (file_exists($file)) {
+			unlink($file);
+		}
+
+		$dir = $this->pathToViewerApp . '/cypress';
+		if (is_dir($dir)) {
+			$files = new \RecursiveIteratorIterator(
+				new \RecursiveDirectoryIterator($dir, \RecursiveDirectoryIterator::SKIP_DOTS),
+				\RecursiveIteratorIterator::CHILD_FIRST
+			);
+
+			foreach ($files as $fileInfo) {
+				/** @var \SplFileInfo $fileInfo */
+				if ($fileInfo->isLink()) {
+					unlink($fileInfo->getPathname());
+				} else if ($fileInfo->isDir()) {
+					rmdir($fileInfo->getRealPath());
+				} else {
+					unlink($fileInfo->getRealPath());
+				}
+			}
+			rmdir($dir);
+		}
+
+		// re-run the instance verification
+		$this->checker->runInstanceVerification();
+	}
+}