diff --git a/android/src/main/java/io/agora/agora_rtc_ng/VideoViewController.java b/android/src/main/java/io/agora/agora_rtc_ng/VideoViewController.java
index 968a263a8..adc5a95df 100644
--- a/android/src/main/java/io/agora/agora_rtc_ng/VideoViewController.java
+++ b/android/src/main/java/io/agora/agora_rtc_ng/VideoViewController.java
@@ -232,5 +232,6 @@ private long getLong(Object value) {
 
     public void dispose() {
         methodChannel.setMethodCallHandler(null);
+        disposeAllRenderers();
     }
 }
diff --git a/example/ios/Flutter/AppFrameworkInfo.plist b/example/ios/Flutter/AppFrameworkInfo.plist
index 9625e105d..7c5696400 100644
--- a/example/ios/Flutter/AppFrameworkInfo.plist
+++ b/example/ios/Flutter/AppFrameworkInfo.plist
@@ -21,6 +21,6 @@
   <key>CFBundleVersion</key>
   <string>1.0</string>
   <key>MinimumOSVersion</key>
-  <string>11.0</string>
+  <string>12.0</string>
 </dict>
 </plist>
diff --git a/example/ios/Podfile b/example/ios/Podfile
index 062114f3a..070fb68e2 100644
--- a/example/ios/Podfile
+++ b/example/ios/Podfile
@@ -1,5 +1,5 @@
 # Uncomment this line to define a global platform for your project
-platform :ios, '11.0'
+platform :ios, '12.0'
 
 # CocoaPods analytics sends network stats synchronously affecting flutter build latency.
 ENV['COCOAPODS_DISABLE_STATS'] = 'true'
diff --git a/example/ios/Runner.xcodeproj/project.pbxproj b/example/ios/Runner.xcodeproj/project.pbxproj
index bb4699101..ac0c729dd 100644
--- a/example/ios/Runner.xcodeproj/project.pbxproj
+++ b/example/ios/Runner.xcodeproj/project.pbxproj
@@ -251,7 +251,7 @@
 		97C146E61CF9000F007C117D /* Project object */ = {
 			isa = PBXProject;
 			attributes = {
-				LastUpgradeCheck = 1430;
+				LastUpgradeCheck = 1510;
 				ORGANIZATIONNAME = "";
 				TargetAttributes = {
 					71BBA3B728AB50E2007B0DBC = {
@@ -488,7 +488,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SUPPORTED_PLATFORMS = iphoneos;
@@ -543,7 +543,7 @@
 				INFOPLIST_FILE = ScreenSharing/Info.plist;
 				INFOPLIST_KEY_CFBundleDisplayName = ScreenSharing;
 				INFOPLIST_KEY_NSHumanReadableCopyright = "";
-				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -580,7 +580,7 @@
 				INFOPLIST_FILE = ScreenSharing/Info.plist;
 				INFOPLIST_KEY_CFBundleDisplayName = ScreenSharing;
 				INFOPLIST_KEY_NSHumanReadableCopyright = "";
-				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -616,7 +616,7 @@
 				INFOPLIST_FILE = ScreenSharing/Info.plist;
 				INFOPLIST_KEY_CFBundleDisplayName = ScreenSharing;
 				INFOPLIST_KEY_NSHumanReadableCopyright = "";
-				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -680,7 +680,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = iphoneos;
@@ -729,7 +729,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 11.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				SUPPORTED_PLATFORMS = iphoneos;
diff --git a/example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme b/example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme
index a6b826db2..5e31d3d34 100644
--- a/example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme
+++ b/example/ios/Runner.xcodeproj/xcshareddata/xcschemes/Runner.xcscheme
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "1430"
+   LastUpgradeVersion = "1510"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
diff --git a/example/ios/Runner/AppDelegate.swift b/example/ios/Runner/AppDelegate.swift
index 70693e4a8..b63630348 100644
--- a/example/ios/Runner/AppDelegate.swift
+++ b/example/ios/Runner/AppDelegate.swift
@@ -1,7 +1,7 @@
 import UIKit
 import Flutter
 
-@UIApplicationMain
+@main
 @objc class AppDelegate: FlutterAppDelegate {
   override func application(
     _ application: UIApplication,
diff --git a/ios/Classes/AgoraRtcNgPlugin.m b/ios/Classes/AgoraRtcNgPlugin.m
index cb4158996..0a670bd0a 100644
--- a/ios/Classes/AgoraRtcNgPlugin.m
+++ b/ios/Classes/AgoraRtcNgPlugin.m
@@ -8,6 +8,8 @@ @interface AgoraRtcNgPlugin ()
 
 @property(nonatomic) NSObject<FlutterPluginRegistrar> *registrar;
 
+- (void) dispose;
+
 @end
 
 @implementation AgoraRtcNgPlugin
@@ -57,4 +59,20 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
   }
 }
 
+- (void)detachFromEngineForRegistrar:(NSObject<FlutterPluginRegistrar> *)registrar {
+    [self dispose];
+}
+
+- (void) dispose {
+    if (self.videoViewController) {
+        [self.videoViewController dispose];
+        self.videoViewController = NULL;
+    }
+}
+
+- (void)dealloc
+{
+    [self dispose];
+}
+
 @end
diff --git a/shared/darwin/TextureRenderer.mm b/shared/darwin/TextureRenderer.mm
index 52de2b031..00e3a4bc8 100644
--- a/shared/darwin/TextureRenderer.mm
+++ b/shared/darwin/TextureRenderer.mm
@@ -64,7 +64,7 @@ void OnVideoFrameReceived(const void *videoFrame,
             }
             dispatch_semaphore_signal(renderer.lock);
             
-            if (renderer.isDirtyBuffer) {
+            if (renderer.textureRegistry && renderer.isDirtyBuffer) {
                 [renderer.textureRegistry textureFrameAvailable:renderer.textureId];
             }
         }
@@ -126,13 +126,19 @@ - (void)updateData:(NSNumber *)uid channelId:(NSString *)channelId videoSourceTy
 }
 
 - (void)dispose {
-    self.irisRtcRendering->RemoveVideoFrameObserverDelegate(self.delegateId);
+    if (self.irisRtcRendering) {
+        self.irisRtcRendering->RemoveVideoFrameObserverDelegate(self.delegateId);
+        self.irisRtcRendering = NULL;
+    }
     if (self.delegate) {
         delete self.delegate;
         self.delegate = NULL;
     }
-    [self.textureRegistry unregisterTexture:self.textureId];
-    if (self.isDirtyBuffer) {
+    if (self.textureRegistry) {
+        [self.textureRegistry unregisterTexture:self.textureId];
+        self.textureRegistry = NULL;
+    }
+    if (self.buffer_cache && self.isDirtyBuffer) {
       CVPixelBufferRelease(self.buffer_cache);
       self.buffer_cache = NULL;
     }
diff --git a/shared/darwin/VideoViewController.h b/shared/darwin/VideoViewController.h
index a2924f5ab..05df1b796 100644
--- a/shared/darwin/VideoViewController.h
+++ b/shared/darwin/VideoViewController.h
@@ -28,6 +28,8 @@
 
 - (BOOL)destroyTextureRender:(int64_t)textureId;
 
+- (void)dispose;
+
 @end
 
 
diff --git a/shared/darwin/VideoViewController.mm b/shared/darwin/VideoViewController.mm
index aafeab18f..74a6ca43d 100644
--- a/shared/darwin/VideoViewController.mm
+++ b/shared/darwin/VideoViewController.mm
@@ -132,8 +132,6 @@ @interface VideoViewController ()
 @property(nonatomic) PlatformRenderPool* platformRenderPool;
 
 @property(nonatomic, strong) FlutterMethodChannel *methodChannel;
-
-- (void)dispose;
 @end
 
 @implementation VideoViewController