While testing my app one of the actions I did is to clean install from PlayStore and then install update from my computer. When I did so I received the error INSTALL_FAILED_VERSION_DOWNGRADE, there are a-lot of information in Google about this error I understood that I need to increase the versionCode in build grade file, and I did so.
But then I started to receive the following error: INSTALL_FAILED_UPDATE_INCOMPATIBLE: Package ###### signatures do not match previously installed version; ignoring!.
All suggestions that I can find are about uninstalling the app from the device and then perform a clean install, and it does work. My question is why it happened? I am really concerned about the customers who already have this app installed, will they be able to update as well?
Thanks for your answers
This means, that the two APKs are signed with different signing keys. If you try to install a debug version, the APK is signed with a debug key. So it is normal that the installation will fail.
In order to test the update of your app, either create a release version of your app (e.g. by selecting "release" from the "Build variants" tab. Or add the signing release configurations to your debug build variant in the app module's build.gradle file.