How to update an app?

[Raphaël MANSUY]

Hi,

When I want to publish a new version of an app, I use the "update" button and upload a new version of my app. But on my smartphone, after downloading the new version, the Telerik app manager reports this error : "an application with the same signature is already installed"...
Which setting do you use for this test? (I don't change anything in my app, except the version number...)

[Martin Yankov]

Hello Raphaël,

Android shows an error message "An existing package by the same name with a conflicting signature is already installed" when the two apps have been signed with different developer identities. Most probably one of the app versions is build in debug mode with a debug identity and the other one is signed with your developer identity. You need to sign app updates with the same identities for them to install on top of the previous version. Otherwise, you can uninstall the previous version from Android settings and install the new update.

If you are building your package with Telerik AppBuilder and use the "Build" button, the package is always signed with the debug identity. Only the "Publish" feature signs the package with your identity.

Let me know if you have any other questions or experience more problems.

Regards,
Martin Yankov
Telerik

 

 

[Raphaël MANSUY]

I'm using VS.NET Xamarin plugin to build my package.
I always build it in "Release" mode...

What do you mean by "identity"? what does it change in the package?

[Martin Yankov]

Hi Raphaël,

According to the Xamarin documentation, building an Android package in Debug or Release modes still signs the package with a new debug signing-key (cryptographic identity). To properly sign you Android package, you need to set the Build configuration to "Release" and then go to Tools -> Publish Android Application. This will not publish your app in Google Play. It will let you sign your app with your signing-key (or create a new one) and it will build the package. Here is a link to a documentation article for reference: Xamarin - Preparing an Application for Release. Search for "Signing the APK in Visual Studio".

You should do this every time you release an app or an app update to avoid signature conflicts. Otherwise, the Xamarin plugin creates a new debug signing-key for your app every time and the update cannot be applied to an older version.

Let me know if this information helps.

Regards,
Martin Yankov
Telerik

 

 

[Raphaël MANSUY]

yes, that's how I build my package... using always the same key store.
Is there a way I can check the signature of the apk file?

[Martin Yankov]

Hello Raphaël,

You can do the following. Go to your Java folder -> jdk -> bin and open a command prompt there. Type in "jarsigner -verify -verbose -certs path_to_your_apk.apk". If you see "CN=Android Debug", then this app was signed with a debug certificate. If you see some other CN, then the app was properly signed.

Please, try this out and let me know the outcome.

Regards,
Martin Yankov
Telerik

 

 

[Raphaël MANSUY]

thanks Martin,
I see my company name in the CN field...
But still the same error when I upload a new version...

[Raphaël MANSUY]

One of my customers says that the update works fine on his smartphone, no need to uninstall the previous one...
So, could this error be related to the smartphone used?

[Martin Yankov]

Hello Raphaël,

I cannot reproduce the issue on the devices here. Can you try to uninstall the app from your device, install the old version with AppManager and then update to the new version again with AppManager, so you can confirm the issue?

If you experience the problem again, please, provide information on the device you are using. Also, it will be ideal if you can open a support ticket and send us the .apk files you tested with.

I am looking forward to your reply.

Regards,
Martin Yankov
Telerik