The Signing Fingerprint You Specified Is Already Used by Another Android Oauth2 Client

The signing fingerprint you specified is already used by another Android OAuth2 client

This error occurs when there is an existing SIGNING CERTIFICATE FINGERPRINT (SHA1) on Google Developers linked to a different account.

Solution is to delete the project that is using that SHA1 in console.developers.google.com for the old/incorrect project.

You cannot change the SHA1 fingerprint once it is set.
Remember that deleting the project takes 7 days to completely remove it.

Another option is to delete the debug.keystore and generate a new one with:

keytool -genkey -v -keystore debug.keystore -alias androiddebugkey
-storepass android -keypass android -keyalg RSA -validity 14000

Remember you have to uninstall the app otherwise you get the [INSTALL_FAILED_UPDATE_INCOMPATIBLE] error.

The fingerprint you specified is already used by an Android OAuth2 client ID in this project or another project

I finally got a useful response from Google support through email, providing just a clue on how to start the recovery process:

I understand you're receiving a Client ID error when trying to link your app to a Game Services project. This error message is displayed because your package ID and SHA1 are already in use by another Client ID.

To resolve this issue, please use the steps below to delete the Client ID from your Google Developers Console (formerly Cloud Console).

Important: Do not delete the Google Developers Console project before deleting the Client ID. If you’ve already deleted the project, you will need to undelete it from your Projects list.

1. Use the following URL to access the project - https://console.developers.google.com/project/186639667931
2. Select APIs & auth > Credentials
3. Under “Client ID for Android application” click the “Delete” button.
4. Try linking your app in the Play Console again. If you’re unable to view or undelete the project linked in step 1, please try accessing it while logged in with the primary email address on your Play developer account.

There was no 'Client ID for Android application', but there was an 'OAuth Client' under 'OAuth 2.0 client IDs', so I deleted that. That still had an old SHA1 number as it wouldn't take my current one. So I wasn't really deleting something with my current number, but deleting this deleted the whole client and brought up a blank screen. Here there was a bit of a trap. I added my current SHA1 number to that screen, which it accepted. Now I was able to get a response from the Google Play site again from my app, although its response always was 'Cannot access services'.

As it turns out, this screen was the default screen, which is 'Google Play Android Developer'. I'll have to research what this is for sometime, but what I needed to add a SHA1 to was my actual app name. I ultimately found buried in the dropdown list at the very top, next to 'Google APIs', among example apps I had downloaded and 'Google Play Android Developer'. I still couldn't add my current SHA1 to it until I went back and deleted the 'OAuth Client' from 'Google Play Android Developer'. This bought the same default screen back, so I went back to the dropdown, selected my app name, and then was able to finally add my current SHA1 back to it.

So deleting a SHA1 appears not to be a permanent exile from Play Services, just the start of a tricky process to get it reestablished.

An OAuth2 client already exists for this package name and SHA-1 in another project

So the answer is well written in the error. You can't have two projects of same package name. Even if you delete it. It will take alteast 4-5 days to get deleted fully from developer's console.

So only solution is to generate a new SHA-1 key by custom signing the app by generating a signed apk from android studio. Or just create a new project with different package name both ways will work for now.

Hope this info helps. Do let me know if it changes anything for you.

EDIT: I encourage you to go through these official Google docs on signing apk to understand this process.

Getting duplicate fingerprint error while updating SHA-1 fingerprint for Android oAuth2 Client ID

I found a fix to this problem.

When the console asks you for the SHA1 and Package name for a new API that you are using in the same app.

Just keep the same SHA1 code and change the Package name a little.
Eg: com.example.exampleapp to com.example.exampleapp1 .

I know this is not a full proof solution but i have many different google API calls in my app by just changing the package name a little.

I tried many solution from This but my simple fix helped me move on.

Hope this helps you.

---

Related Topics