SSH access problem after SSH client update

ia In OpenSSH 7.0 the support for ssh-dss host and user keys was disabled by default. If you are using a ssh-dss key (the public key starts with "ssh-dss") you will not be able to login to the SC systems by using the default settings after updating your local SSH installation.
In this case a verbose SSH-run

ssh -v <user>@<system>

will display you the following message:

debug1: Skipping ssh-dss key /.../.ssh/id_dsa for not in PubkeyAcceptedKeyTypes

To fix this problem, please upload a new key (using the "ssh-rsa" key format) via JuDoor.