This page offers tips and troubleshooting for Android-specific issues
that you might encounter when using Firebase.
Have other challenges or don't see your issue outlined below? Make sure to check
out the main Firebase FAQ for more pan-Firebase or
product-specific FAQ.
You can also check out the
Firebase Android SDK GitHub repo
for an up-to-date list of reported issues and troubleshooting. We encourage you
to file your own Firebase Android SDK related issues there, too!
I'm getting an error that the ktx library failed to resolve or
could not be found.
This error is likely because you're using the Firebase BoM and
specifying a KTX module as your product library dependency.
In July 2025, we stopped releasing new versions of the KTX modules,
and we removed the KTX libraries from the Firebase Android BoM
(v34.0.0).
If you use KTX APIs from previously released KTX modules, we recommend
that you migrate your app to use KTX APIs from the main modules
instead. For details, see the
FAQ about this initiative.
How do I resolve this error: "An OAuth2 client already exists for this
package name and SHA-1 in another project"?
This error occurs if we detect that another Firebase or Google Cloud
project contains an OAuth 2.0 client ID with the package name
and SHA-1 that you specified. Learn how to
resolve this error.
When I add Firebase to my Android project, I get a "Could not find" error.
This error usually means that your app is missing one or more references
to Google's Maven repository. Make sure to include Google's Maven repository
(google()) in your Gradle Configuration file.
- If your project is using the
plugins syntax, include it
in the plugins section in your
settings.gradle.kts or settings.gradle file.
- If your project is using the
buildscript syntax, include
it in both the buildscript and allprojects
sections in your project-level build.gradle.kts or
build.gradle file.
When I add a Firebase SDK to my Android project, I get an error about
invoke-custom support and enabling desugaring.
In May 2021 (Firebase BoM v28.0.0), Firebase disabled desugaring for all its
Android libraries
(see release note).
This change means that Gradle builds that use Android Gradle plugin (AGP) v4.2
or earlier need to enable Java 8 support. Otherwise, when adding a Firebase SDK,
these Android projects get the following build failure:
D8: Invoke-customs are only supported starting with Android O (--min-api 26)
Caused by: com.android.builder.dexing.DexArchiveBuilderException: Error while dexing.
The dependency contains Java 8 bytecode. Please enable desugaring by adding the following to build.gradle
android {
compileOptions {
sourceCompatibility 1.8
targetCompatibility 1.8
}
}
See https://developer.android.com/studio/write/java8-support.html for details.
Alternatively, increase the minSdkVersion to 26 or above.
To fix this build failure, you can follow one of two options:
- Add the listed
compileOptions from the error message to your app-level
build.gradle.kts or build.gradle file.
- Increase the
minSdkVersion for your Android project to 26 or above.
Google Sign-in is showing the error "12500:" after I released my app. How
do I fix it?
There are two possible reasons why this would happen: you haven’t provided a
support email or you’re missing a SHA key. In order to fix this error, make
sure all of these conditions are true:
How to add Firebase plugins to an Android project using the buildscript
syntax?
Firebase has the following Gradle plugins:
| Plugin name |
Maven coordinates |
Latest version |
Plugin ID |
| Google Play services plugin |
com.google.gms:google-services |
4.4.4 |
com.google.gms.google-services |
| App Distribution plugin |
com.google.firebase:firebase-appdistribution-gradle |
5.2.0 |
com.google.firebase.appdistribution |
| Crashlytics plugin |
com.google.firebase:firebase-crashlytics-gradle |
3.0.6 |
com.google.firebase.crashlytics |
| Performance Monitoring plugin |
com.google.firebase:perf-plugin |
2.0.2 |
com.google.firebase.firebase-perf |
Here's how to add a Firebase plugin to an Android project that still uses the
buildscript syntax:
In your root-level (project-level) Gradle file
(<project>/build.gradle.kts or <project>/build.gradle), add the plugin as
a dependency using its Maven coordinates:
Kotlin
buildscript {
repositories {
// Make sure that you have the following two repositories
google() // Google's Maven repository
mavenCentral() // Maven Central repository
}
dependencies {
...
// Add the Maven coordinates and latest version of the plugin
classpath ("PLUGIN_MAVEN_COORDINATES:PLUGIN_VERSION")
}
}
allprojects {
...
repositories {
// Make sure that you have the following two repositories
google() // Google's Maven repository
mavenCentral() // Maven Central repository
}
}
Groovy
buildscript {
repositories {
// Make sure that you have the following two repositories
google() // Google's Maven repository
mavenCentral() // Maven Central repository
}
dependencies {
...
// Add the Maven coordinates and latest version of the plugin
classpath 'PLUGIN_MAVEN_COORDINATES:PLUGIN_VERSION'
}
}
allprojects {
...
repositories {
// Make sure that you have the following two repositories
google() // Google's Maven repository
mavenCentral() // Maven Central repository
}
}
In your module (app-level) Gradle file (usually
<project>/<app-module>/build.gradle.kts or
<project>/<app-module>/build.gradle), add the plugin using its
plugin ID:
Kotlin
plugins {
id("com.android.application")
// Add the ID of the plugin
id("FIREBASE_PLUGIN_ID")
...
}
Groovy
plugins {
id 'com.android.application'
// Add the ID of the plugin
id 'FIREBASE_PLUGIN_ID'
...
}
