Update Chplay version 2

I published version 1 and then published it on chplay store. I need to upgrade version 2 but the system says it cannot be installed. I the apk to try installing but still can’t install. Only when I delete the old app can I install the new version. But for chplay it is not possible because this is an update.
Both keystore and pakagename are correct.

Read the detailed message from Google
you might want to show us the mentioned screenshot…

Taifun