Need help with OpenSuSE Tumbleweed `cd:/content: Invalid signature. Installation aborted.`

This succeeded: https://openqa.opensuse.org/tests/overview?distri=opensuse&version=Tumbleweed&build=20160901&groupid=1 installing the image from http://download.opensuse.org/tumbleweed/iso/openSUSE-Tumbleweed-DVD-x86_64-Current.iso.mirrorlist (for which the md5 and sha signatures match).

But I got this cd:/content: Invalid signature. Installation aborted. message:

After a few statements [WayBack] in the install shell:

mkdir /mnt/cd
mount /dev/cdrom /mnt/cd
cd /mnt/cd
gpg --import content.key
gpt --verify content.asc

Indeed the cd:/content didn’t verify as content.key wasn’t a trusted signature:

How to proceed?

–jeroen