I got same issue. Just today. When I try to run locally, I got the exact same error. To get it run again, I update the field compileSdkVersion and targetSdkVersion in file android > build.gradle from 29 to 30. Then, it can run again. If this answer fits with you, you can go with this way. But, personally, I'm lookin for solution without to change the value compileSdkVersion and targetSdkVersion

Update: just change the compileSdkVersion

The issue was just what I guessed. So, some updates to a minor version/patch version of an android dependency caused all this today.

To solve this, for the dependencies in your build.gradle file, if you have specified it to take the latest minor/patch version every time you build it, make it take an exact stable version.

For example, my appcompact dependecy was,

implementation "androidx.appcompat:appcompat:1.+

This means that it can update to 1.2.x or 1.3.x etc.. as and when such version updates get published. I changed this to depend on an exact stable version like below,

implementation "androidx.appcompat:appcompat:1.3.0"

Hopefully, this solves the issue for everyone.

Observing the same core library dependency is causing Gradle build issues for all.

Also, clean project or Invalidate Caches/Restart... options wouldn't help here.

Affecting dependency: 'androidx.core:core-ktx:1.7.0-alpha01'

This dependency which was causing issue, for that I have made it stable in build.gradle file, then added a new line to solve dependency conflicts:

configurations.all {
   resolutionStrategy {
     force 'androidx.core:core-ktx:1.6.0'
   }
}

For me the issue is caused by react-native-netinfo 's old version 4.0.0 which was configured to automatically pick up the latest published package of androidx.core... So in that case it did I realized androidx.core.core-1.7.0-alpha01 had been published right as the issue started occurring.

So to fix that I updated my react-native-netinfo package from 4.0.0 to 6.0.0 and this issue was resolved for me.

Apparently they just broke this today.

You can fix it by adding the following line to your app level build.gradle file (above the android { } block as a sibling):

configurations.all {
    resolutionStrategy { force 'androidx.core:core-ktx:1.6.0' }
}

Finally, the Gradle build was successfully completed. Ref. https://docs.gradle.org/current/dsl/org.gradle.api.artifacts.ResolutionStrategy.html

Simple work around with complie version

• Change compileSdkVersion=29 to compileSdkVersion=30 and sync.

If you not willing to change the complie version,then

 configurations.all {
        resolutionStrategy {
            force 'androidx.core:core-ktx:1.6.0'
        }
    }

add the above code in build.gradle inside android and apply this

implementation 'androidx.core:core-ktx:1.7.0-alpha01'

Here is a screenshot of what I have done and it's run perfectly. change these lines from

 compileSdkVersion = 29
 targetSdkVersion = 29

to

 compileSdkVersion = 30
 targetSdkVersion = 30

and also change this line from

implementation 'androidx.appcompat:appcompat:1.+'

to implementation 'androidx.appcompat:appcompat:1.3.0'

As some has mentioned, the problem is that the RN build automatically "upgraded" to androidx.core:core:1.7.0-alpha01, which depends on SDK version 30.

The Fix

The fix is simply to specify android core version via androidXCore in build.gradle

buildscript {
    ext {
        buildToolsVersion = "29.0.3"
        minSdkVersion = 23
        compileSdkVersion = 29
        targetSdkVersion = 29
        ndkVersion = "20.1.5948944"
        kotlin_version = "1.5.0"
        androidXCore = "1.5.0"
    }

How I figured it out

Figuring this out was painful. I grepped for gradle files that would automatically upgrade packages like so

find . -name '*.gradle' -exec grep -H "\.+" {} \;

and found in node_modules/@react-native-community/netinfo/android/build.gradle the following snippet

def androidXCore = getExtOrInitialValue('androidXCore', null)
  if (supportLibVersion && androidXVersion == null && androidXCore == null) {
    implementation "com.android.support:appcompat-v7:$supportLibVersion"
  } else {
    def defaultAndroidXVersion = "1.+"
    if (androidXCore == null) {
      androidXCore = androidXVersion == null ? defaultAndroidXVersion : androidXVersion
    }
    implementation "androidx.core:core:$androidXCore"
  }
}

Try to add this on your top build.gradle at the bottom of buildscript. This will force anything to a specific version.

subprojects {
    project.configurations.all {
        resolutionStrategy.eachDependency { details ->
            if (details.requested.group == 'androidx.core'
                    && !details.requested.name.contains('androidx') ) {
                details.useVersion "1.5.0"
            }
            
            if (details.requested.group == 'androidx.core-ktx'
                    && !details.requested.name.contains('androidx') ) {
                details.useVersion "1.5.0"
            }
        }
    }
}

Updating version numbers to match those shown in the official template build.gradle file worked for me: https://github.com/facebook/react-native/blob/master/template/android/build.gradle

 buildToolsVersion = "30.0.2"
 compileSdkVersion = 30
 targetSdkVersion = 30
 ndkVersion = "21.4.7075529"

First never use + to define the version of Libraries in Gradle, Try to give the latest version always.

If you are using Core KTX like below in your main Gradle dependencies

implementation "androidx.core:core-ktx:+"

Just replace it to

implementation "androidx.core:core-ktx:1.6.0"

Core and Core-ktx Version 1.7.0 released yesterday(September 1, 2021), which is causing the issues.

https://developer.android.com/jetpack/androidx/releases/core

None of the single solutions above worked, but a combo of them worked for me, using RN 0.63.3 Here's the diff:

diff --git a/android/app/build.gradle b/android/app/build.gradle
index 9c014f8..1b59f65 100644
--- a/android/app/build.gradle
+++ b/android/app/build.gradle
@@ -139,6 +139,12 @@ def enableProguardInReleaseBuilds = false
  */
 def jscFlavor = 'org.webkit:android-jsc:+'
 
+configurations.all {
+   resolutionStrategy {
+     force 'androidx.core:core-ktx:1.6.0'
+   }
+}
+
 android {
     compileSdkVersion rootProject.ext.compileSdkVersion
 
diff --git a/android/build.gradle b/android/build.gradle
index a32892e..db64506 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -3,12 +3,13 @@
 buildscript {
     ext.kotlin_version = '1.4.0'
     ext {
-        buildToolsVersion = "29.0.2"
+        buildToolsVersion = "29.0.3"
         minSdkVersion = 21
-        compileSdkVersion = 30
+        compileSdkVersion = 29
         targetSdkVersion = 29
         androidXAnnotation = "1.1.0"
         androidXBrowser = "1.0.0"
+        androidXCore = "1.5.0"
     }
     repositories {
         google()