Play Console has changed app signing

Hi,

I am trying to upload air Apps (apks signed with a self signed certificate) and used Animate CC for creating the signed apk.

Now Google play console wants me to upload updates with an upload_cert which is in .der format.

Google App signing is turned on permanantly and i can not opt out

As far as I know a .p12 file which is needed for signing with Animate does contain a private key, while the upload_cert.der provided from the Play Console for my app does not include a private key.

So how do i generate a new p12 file with which I can create signed apks that are not rejected by google?

When I upload an update signed with my private key I get the uploaderror message:

.........................................

Upload failed

You uploaded an APK that is not signed with the upload certificate. You must use the same certificate. The upload certificate has fingerprint:

[ SHA1: ++++++++++++++++++  ]

and the certificate used to sign the APK you uploaded have fingerprint:

[ SHA1: ---------------------------   ]

..........................................................

When I create a p12 with openssl and my private key, my certificate and the upload_cert I get the same upload error.

my Questions are:

1. Is there a trick to opt out of Google app signing programm?

2. Is there a way to generate a valid p12 file based on the upload_cert.der?

Any Ideas, help, suggestions are welcome!