Manually installing an updated APK fails with "signatures do not match the previously installed version"

Question

I've built a silly app to share among a few friends. No need to put it up on the app-store.

I built the first apk (signed), uploaded it to a web-server and all worked well.

A small issue arose, I fixed it, re-built, signed with the same keystore and uploaded it again. It now seems that I am unable to install from the new apk. The debugger tells me:

signatures do not match the previously installed version 

So I uninstalled the old version by opening the app drawer and dragging it onto the "uninstall" button. When opening "Settings -> Apps", I don't see it anywhere anymore. I don't see any traces of the app on my device.

Yet I still get the above error message.

Is it possible some information still lingers on the device somewhere? Is there any way I can verify that?

Answer 1

Yes It is possible if somehow your old application is not removed 100% or its data is not removed.

Try:

adb uninstall "com.yourapp.yourapp" 

If you don't know exactly what to put as replacement for "com.yourapp.yourapp", then you just open Android studio, Run your app while it is connected to a device and then look at Debug window.

It says:

 Waiting for device.  Target device: samsung-sm_t531-xxxxxxxxx  Uploading file  local path: C:\Users\myapp\app\build\outputs\apk\myapp.apk  remote path: /data/local/tmp/com.myapp.myapp  Installing com.myapp.myapp  DEVICE SHELL COMMAND: pm install -r "/data/local/tmp/com.myapp.myapp"  pkg: /data/local/tmp/com.myapp.myapp  Success 

com.myapp.myapp in this case is the name of the package you must use to uninstall.