Repository: flutter
Issue: Exclamation marks and hot reload problems after update to macOS Big Sur, antivirus
Labels: platform-ios,tool,engine,platform-mac,dependency: dart,t: hot reload,a: typography,customer: crowd,P2,found in release: 1.22,platform-bigsur,found in release: 1.24,team-ios,triaged-ios

Hello everyone,

Since the update to macOS Big Sur I have two problems when developing apps on iOS. On Android everything runs fine. I have already reinstalled Xcode but without success.

First problem: 
When running the app, some or almost all texts are displayed as exclamation marks.
[Image](https://user-images.githubusercontent.com/52165058/99635837-d8e49800-2a42-11eb-83b7-b9f09eb5e65e.png)


Second problem: 
The hot reload does not work anymore and returns this error message.

```
[   +1 ms] Performing hot reload...
[  +15 ms] Scanned through 676 files in 9ms
[        ] Syncing files to device iPhone 11...
[        ] Compiling dart to kernel with 1 updated files
[   +1 ms] <- recompile package:feuerwehrquiz/main.dart 8dc59acf-6daf-4781-8cee-c0b8e298e7ca
[        ] package:feuerwehrquiz/presentation/question_v2/components/wordline_mode/wordline_prefix_row.dart
[        ] <- 8dc59acf-6daf-4781-8cee-c0b8e298e7ca
[  +91 ms] Updating files.
[   +6 ms] DevFS: Sync finished
[        ] Syncing files to device iPhone 11... (completed in 101ms)
[        ] Synced 0.1MB.
[  +42 ms] <- reject
[ +104 ms] Hot reload was rejected:
[   +1 ms] Error while starting Kernel isolate task.
           Try performing a hot restart instead.
[   +2 ms] Performing hot reload... (completed in 269ms)
[        ] Try again after fixing the above error(s).
```

Does anyone have the problem or knows how I can solve it?
Thanks a lot for your help :)



<details>
  <summary>Logs</summary>

`flutter doctor -v`

```
[✓] Flutter (Channel master, 1.24.0-8.0.pre.304, on macOS 11.0.1 20B29
    darwin-x64, locale de)
    • Flutter version 1.24.0-8.0.pre.304 at /Users/sstiels/5v3n/flutter
    • Framework revision c6290500f8 (5 hours ago), 2020-11-18 17:29:28 -0800
    • Engine revision 35a0b9fe68
    • Dart version 2.12.0 (build 2.12.0-50.0.dev)

[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.1)
    • Android SDK at /Users/sstiels/Library/Android/sdk
    • Platform android-30, build-tools 30.0.1
    • Java binary at: /Applications/Android
      Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6222593)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 12.2)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 12.2, Build version 12B45b
    • CocoaPods version 1.9.3

[✓] Android Studio (version 4.0)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 48.1.2
    • Dart plugin version 193.7361
    • Java version OpenJDK Runtime Environment (build
      1.8.0_242-release-1644-b3-6222593)

[✓] VS Code (version 1.51.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.16.0

[✓] Connected device (1 available)
    • iPhone 11 (mobile) • A411318D-D355-434F-92D2-1F5EA704CA22 • ios •
      com.apple.CoreSimulator.SimRuntime.iOS-14-2 (simulator)

• No issues found!
```

</details>