Hi, this is the output of the **adb** command: 'Android Debug Bridge version 1.0.39
Version 1:8.1.0+r23-5ubuntu2
Installed as /usr/lib/android-sdk/platform-tools/adb

global options:..
.

environment variables:
 $ADB_TRACE
     comma-separated list of debug info to log:
     all,adb,sockets,packets,rwx,usb,sync,sysdeps,transport,jdwp
 $ADB_VENDOR_KEYS         colon-separated list of keys (files or directories)
 $ANDROID_SERIAL          serial number to connect to (see -s)
 $ANDROID_LOG_TAGS        tags to be used by logcat (see logcat --help)
'
and this is the output of the 'flutter doctor -v' command

'
[✓] Flutter (Channel stable, 1.20.3, on Linux, locale fr_FR.UTF-8)
    • Flutter version 1.20.3 at /home/coach/Documents/development/flutter
    • Framework revision 216dee60c0 (il y a 2 semaines), 2020-09-01 12:24:47 -0700
    • Engine revision d1bc06f032
    • Dart version 2.9.2

[!] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
    • Android SDK at /home/coach/Android/Sdk
    • Platform android-30, build-tools 30.0.2
    • Java binary at: /snap/android-studio/91/android-studio/jre/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)
    ! Some Android licenses not accepted.  To resolve this, run: flutter doctor --android-licenses

[✓] Android Studio (version 4.0)
    • Android Studio at /snap/android-studio/91/android-studio
    • Flutter plugin version 49.0.2
    • Dart plugin version 193.7547
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)
[✓] Connected device (1 available)
    • AOSP on IA Emulator (mobile) • emulator-5554 • android-x86 • Android 9 (API 28) (emulator)
! Doctor found issues in 1 category.
'
by the way, the *flutter doctor --android-licenses* command doesn't resolve the problem!