When you start samba-ad-dc using the command `$ sudo systemctl start samba-ad-dc`, and check either /var/log/samba/log.smbd or /var/log/samba/%m, it appears that port 53 is unavailable.
Apache suddenly crashes, and upon checking the logs, I found the following messages: "AH00050: Child 7815 returned a Fatal error... Apache is exiting!" and "AH02818: MPM run failed, exiting."
<Error><Message>Please provide valid credentials. Bearer realm="yahooapis.jp", error="insufficient_scope", error_description="insufficient scope"</Message></Error>
I encountered the above error when using Yahoo's Store API.
A complete Ansible playbook to install Docker CE on Ubuntu 16.04 — apt key, repository registration, and the docker-ce package install in one playbook.