Update 2.x to 3.0.50 failed due to apt.conf

Hey there,
I'm trying to upgrade my OMV 2.x setup to 3.0.50.
If I run: omv-release-upgrade it tells me:

Upgrading system to 3.0 (Erasmus) ...
sed: can't read /etc/apt/apt.conf: No such file or directory
run-parts: /tmp/tmp.7Xc6pFlYSw/pre.d/20-apt-update-source-list exited with return code 2

How can I fix this?

Have a nice day
LouBen3010

touch /etc/apt.conf did the trick for me.
But after that the whole update went wrong.

Sometimes errors about not getting connection to a so called D-BUS and sometimes double nodes in XPath and failing dependencies where all my plugins need OVM >=3.0.23 (but I installed 3.0.50).
I hoped to get the upgrade working because everyone is so excited to use it.

Do you have any hints for the upgrade process?

Thanks for your hints so far.
I just restored my system with a Clonezilla image. So my ownCloud is working again so I can continue my work.

In the evening I will try it again.
I'm afraid of a fresh install, because at this point I invested several hours in configuring all my plugins like Plex, ownCloud, mySQL, nginx.

Or is there a way to fill a fresh installation of OMV 3 with my plugin configs out of my OMV 2 setup?

In the following picture you can see my list of plugins I'm using.