I have deployed a beta application to google play store. But now I want to redeploy a new version of my apk file. But the playstore always tolds me that I have to use the upload signature to do an upload. I used a keystore and added also the uploadsignature to it with this
keytool.exe -importcert -file upload_cert.der -keystore <keystorefile>
What can be the problem. Is there a way to remove completely the beta apk and to add a completely new one without recreating a new app?
You need to look after your signing keys. Luckily you use Google Play App Signing. When you do this, you must sign your APK with a key called an "upload key" then Google Play will sign it for you with the production key.
It sounds like you have lost your upload key. Google Play support can fix this for you if you contact them. You need to follow the steps in this help article