diff --git a/Makefile b/Makefile
index 041a8f3..aa8e36e 100644
--- a/Makefile
+++ b/Makefile
@@ -7,7 +7,7 @@ source_dir=$(build_dir)/source
 sign_dir=$(build_dir)/sign
 package_name=$(app_name)
 cert_dir=$(CURDIR)/../../key
-version+=0.0.28
+version+=0.0.29
 
 all: appstore
 
diff --git a/appinfo/info.xml b/appinfo/info.xml
index 5a5c902..d4a2ef6 100644
--- a/appinfo/info.xml
+++ b/appinfo/info.xml
@@ -5,7 +5,7 @@
 	<name>Mind Map</name>
 	<summary>A Mind map editor</summary>
 	<description><![CDATA[This application enables Nextcloud users to open, save and edit mind map files in the web browser. If enabled, an entry in the New button at the top of the web browser the Mindmap file entry appears. When clicked, a new mindmap file opens in the browser and the file can be saved into the current Nextcloud directory.]]></description>
-	<version>0.0.28</version>
+	<version>0.0.29</version>
 	<licence>agpl</licence>
 	<author mail="i@actom.me" homepage="https://actom.me">Jingtao Yan</author>
 	<namespace>Files_MindMap</namespace>
@@ -18,14 +18,11 @@
 	<screenshot small-thumbnail="https://raw.githubusercontent.com/ACTom/files_mindmap/master/screenshots/2-small.png">https://raw.githubusercontent.com/ACTom/files_mindmap/master/screenshots/2.png</screenshot>
 	<screenshot small-thumbnail="https://raw.githubusercontent.com/ACTom/files_mindmap/master/screenshots/3-small.png">https://raw.githubusercontent.com/ACTom/files_mindmap/master/screenshots/3.png</screenshot>
 	<dependencies>
-		<nextcloud min-version="20" max-version="27"/>
+		<nextcloud min-version="20" max-version="28"/>
 	</dependencies>
 	<repair-steps>
 		<install>
 			<step>OCA\Files_MindMap\Migration\InstallStep</step>
 		</install>
-		<uninstall>
-			<step>OCA\Files_MindMap\Migration\UninstallStep</step>
-		</uninstall>
 	</repair-steps>
 </info>
diff --git a/lib/Migration/InstallStep.php b/lib/Migration/InstallStep.php
index ca20356..7626db7 100644
--- a/lib/Migration/InstallStep.php
+++ b/lib/Migration/InstallStep.php
@@ -42,30 +42,6 @@ public function run(IOutput $output) {
             if (!file_exists($coreImagePath) || md5_file($coreImagePath) !== md5_file($appImagePath)) {
                 copy($appImagePath, $coreImagePath);
             }
-        }
-
-        if (version_compare($currentVersion, '19.0.0.4', '<')) {
-            /* Since 19.0.0.beta3, NC has mindmap's mimetype */
-            $configDir = \OC::$configDir;
-            $mimetypealiasesFile = $configDir . 'mimetypealiases.json';
-            $mimetypemappingFile = $configDir . 'mimetypemapping.json';
-
-            $this->appendToFile($mimetypealiasesFile, ['application/km' => 'mindmap', 'application/x-freemind' => 'mindmap', 'application/vnd.xmind.workbook' => 'mindmap']);
-            $this->appendToFile($mimetypemappingFile, ['km' => ['application/km'], 'mm' => ['application/x-freemind'], 'xmind' => ['application/vnd.xmind.workbook']]);
-            $this->logger->info("Add .km,.mm,.xmind to mimetype list.", ["app" => "files_mindmap"]);
-            $this->updateJS->run(new StringInput(''), new ConsoleOutput());
-        }        
-    }
-
-    private function appendToFile(string $filename, array $data) {
-        $obj = [];
-        if (file_exists($filename)) {
-            $content = file_get_contents($filename);
-            $obj = json_decode($content, true);
-        }
-        foreach ($data as $key => $value) {
-            $obj[$key] = $value;
-        }
-        file_put_contents($filename, json_encode($obj,  JSON_PRETTY_PRINT|JSON_UNESCAPED_SLASHES));
+        }    
     }
 }
diff --git a/lib/Migration/UninstallStep.php b/lib/Migration/UninstallStep.php
deleted file mode 100644
index 3e679d0..0000000
--- a/lib/Migration/UninstallStep.php
+++ /dev/null
@@ -1,58 +0,0 @@
-<?php
-namespace OCA\Files_MindMap\Migration;
-
-use OCP\Migration\IOutput;
-use OCP\Migration\IRepairStep;
-use OCP\ILogger;
-use OC\Core\Command\Maintenance\Mimetype\UpdateJS;
-use Symfony\Component\Console\Input\StringInput;
-use Symfony\Component\Console\Output\ConsoleOutput;
-
-class UninstallStep implements IRepairStep {
-
-    /** @var ILogger */
-    protected $logger;
-    protected $updateJS;
-
-    public function __construct(ILogger $logger, UpdateJS $updateJS) {
-            $this->logger = $logger;
-            $this->updateJS = $updateJS;
-    }
-
-    /**
-    * Returns the step's name
-    */
-    public function getName() {
-            return 'Uninstall MindMap';
-    }
-
-    /**
-    * @param IOutput $output
-    */
-    public function run(IOutput $output) {
-        $currentVersion = implode('.', \OC_Util::getVersion());     
-        if (version_compare($currentVersion, '19.0.0.4', '<')) {
-            /* Since 19.0.0.beta3, NC has mindmap's mimetype */
-            $configDir = \OC::$configDir;
-            $mimetypealiasesFile = $configDir . 'mimetypealiases.json';
-            $mimetypemappingFile = $configDir . 'mimetypemapping.json';
-
-            $this->removeFromFile($mimetypealiasesFile, ['application/km' => 'mindmap', 'application/x-freemind' => 'mindmap', 'application/vnd.xmind.workbook' => 'mindmap']);
-            $this->removeFromFile($mimetypemappingFile, ['km' => ['application/km'], 'mm' => ['application/x-freemind'], 'xmind' => ['application/vnd.xmind.workbook']]);
-            $this->logger->info("Remove .km,.mm,.xmind from mimetype list.", ["app" => "files_mindmap"]);
-            $this->updateJS->run(new StringInput(''), new ConsoleOutput());
-        }
-    }
-
-    private function removeFromFile(string $filename, array $data) {
-        $obj = [];
-        if (file_exists($filename)) {
-            $content = file_get_contents($filename);
-            $obj = json_decode($content, true);
-        }
-        foreach ($data as $key => $value) {
-            unset($obj[$key]);
-        }
-        file_put_contents($filename, json_encode($obj,  JSON_PRETTY_PRINT|JSON_UNESCAPED_SLASHES));
-    }
-}