My android studio version is 3.4  and dependencies is
 dependencies {
        classpath 'com.android.tools.build:gradle:3.2.1'
    }

i changed dependencies to 3.4.0 , also cannot fix the sync failed issue.

my current gradles files under  "C:Users"username".gradlewrapperdists" link are
 "gradle-4.6-all"  and " gradle-5.1.1-all "

may i know how should i fix this "sync failed" issue ?
Thank you very much.

below is the sync failed error.

C:/Android/workspace/AndroidPubSub
build.gradle
Failed to resolve: com
Affected Modules: <a href="openFile:C:/Android/workspace/AndroidPubSub/build.gradle">AndroidPubSub</a>
Sync Failed 5 s 228 ms