Update to owncloud desktop client 2.2.4

since about two weeks I have problems updating my Desktop-Client.
I run different Linux - Systems on clients
All are telling: # no public key available - signatures could not be approved

I'm running : OpenSuse 13.2, Ubuntu 14.04, Ubuntu 16.04

Anyone who can help me?
(Already tried to add public key again - what works, but update doesen't work with the error message above)

found some informations that helped:

nevertheless still warning that owncloud uses weak digest algorithm (SHA1) for the key

Did you import the latest key?
from https://software.opensuse.org/download/package?project=isv:ownCloud:desktop&package=owncloud-client

wget http://download.opensuse.org/repositories/isv:ownCloud:desktop/Ubuntu_16.04/Release.key
sudo apt-key add - < Release.key
sudo apt-get update

thanks a lot - now it works perfect for ubuntu 16.04.
In the end I think just forgot to look to the right repository-address ;-(
I will do accordingly for the other OSs