You uploaded new app bundle to update my publication and got the following error: 
It means that you changed package name of your app at some point so the package name after the rebuild doesn't match Google Play package name of your app.
It's easy to fix, just follow our instructions:
- Find Google Play link of your app, it looks like this: https://play.google.com/store/apps/details?id=com.wApp_123456. In this case com.wApp_123456 would be Google Play package name.
- Go to Advanced Edit section of AppsGeyser Dashboard and scroll down to find the current package name.
- Replace it with Google Play package name from Step 1 and click Submit.
- Go to Download section of the Dashboard, rebuild .aab and upload it on Play Console.