Crashplan for Small Business is not supported (as of the time of writing) on any other Ubuntu version than 18.04 LTS. This appears to be related to an Electron/glibc issue which has long been fixed. Unfortunately Crashplan seem unwilling to upgrade their client.
Fortunately there is a workaround. Add this PPA:
sudo add-apt-repository ppa:maarten-fonville/ppa
sudo apt-get update
You will almost certainly need to accept this PPA’s keys:
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv <whatever-the-id-is-in-the-error-message>
I have also seen a mention about patching libnode.so in the crash plan app itself
but I have not tried this.