In ISPConfig, under DNS, I click on `Add new DNS Zone with Wizard`. After filling the form and clicking 'Create DNS-Record', I am returned to the DNS-Zones screen without any records. However, if I add a new zone manually, it works. Kindly advise.
Did you alter the dns wizard template that you use for creating the zone? maybe your template is incomplete.
Yes, I have. I have performed several installations on Ubuntu 16.04 on servers from Linode.com and Contabo.com using this tutorial https://www.rosehosting.com/blog/how-to-install-ispconfig-3-on-ubuntu-16-04/ On Linode's servers, it always works fine. The problem only occurs on Contabo servers.