Description of problem:

The tinc won't automatically start when system boot, though its status is enabled. It didn't report any failure (exit code, etc.), like it had never enabled.

sudo systemctl status tinc@smartquerier
● tinc - Tinc net xxxx
   Loaded: loaded (/usr/lib/systemd/system/tinc@.service; enabled; vendor preset: disabled)
   Active: inactive (dead)

It can be start manually, and works perfect. Means no error in configuration files.

sudo systemctl start tinc@xxxx
sudo systemctl status tinc@xxxx
● tinc - Tinc net xxxx
   Loaded: loaded (/usr/lib/systemd/system/tinc@.service; enabled; vendor preset
   Active: active (running) since Wed 2016-09-07 11:09:15 JST; 1min 10s ago
 Main PID: 2962 (tincd)
    Tasks: 1 (limit: 512)
   CGroup: /system.slice/system-tinc.slice/tinc
           └─2962 /usr/sbin/tincd -n xxxx -D

Sep 07 11:09:15 hhhh systemd[1]: Started Tinc net xxxx.
Sep 07 11:09:15 hhhh tincd[2962]: tincd 1.0.28 starting, debug level 0
Sep 07 11:09:16 hhhh tincd[2962]: /dev/net/tun is a Linux tun/tap device (tap
Sep 07 11:09:16 hhhh tincd[2962]: Ready

Version-Release number of selected component (if applicable):

Name        : tinc
Arch        : x86_64
Version     : 1.0.28
Release     : 1.el7

How reproducible:
Always, after every reboot

Steps to Reproduce:

1. Create a tinc VPN profile, with name xxxx.
   (For testing purpose, just setup one client is sufficient. The "ConnectTo" target could be a fake target. The daemon will just try to reconnect again and again. Sample is available at https://www.digitalocean.com/community/tutorials/how-to-install-tinc-and-set-up-a-basic-vpn-on-ubuntu-14-04)
2. systemctl start tinc@xxxx (test if it can be start correctly)
3. systemctl enable tinc@xxxx
4. systemctl reboot
5. systemctl status

Actual results:
Active: inactive (dead)

Expected results:
Active: active (running) since ...

Additional info:
This problem is also present in EPEL 7. I'll already open a bug report there.