Linux desktop client does not work

As far as I know, a “program.appimage” should run on any Linux distribution out of the box, because it contains all libraries and solves every dependency. But the client package provided at “https://nextcloud.com/install/#install-clients” does not work on Knoppix:

$ ./Nextcloud-2.6.1-x86_64.AppImage

Nextcloud-2.6.1-x86_64.AppImage: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory

So, how can I get the client to work?

Did you try to install libz ?

No, I didn’t, because as far as I know, the Nextcloud.AppImage should bring everything, that is needed.