Gradle sync failed with reason unknown - Android studio 4.2.1 [closed]

Question

Gradle sync failed: Sync failed: reason unknown

Tried solutions

1. Invalidate cache and restart
2. reinstalled android studio and recloned project
3. changed the gradle version
4. removed .gradle and .idea folder
5. run gradle build from cli
6. toggling offline mode
7. Manually pointed gradle files

using Android studio 4.2.1 and gradle 6.5

Answer 1

In your screenshot, there is a infomation bar on top of the editor area "Gradle project sync failed. Basic funtionality will not work." Click the "Show log in finder", you can check the real reason in the log file.

In my case, I found “ Module: 'xxxxx' platform 'android-26' not found” which mean the platform 26 is missing. After download the platform api level 26, problem solved.

Answer 2

There is great post here: https://www.tehrir.com/gradle-sync-failed in this matter.

Make sure your Android Gradle Plugin version matches Gradle version according to this page: https://developer.android.com/studio/releases/gradle-plugin#updating-gradle

If it matches and still gives same error try upgrading to a higher "tier":

4.2.1 and 6.7.1

It worked for me.