Unit app.service is not loaded properly: Exec format error

Failed to restart app.service: Unit app.service is not loaded properly: Exec format error

[Unit]
Description=Openvmi Xvfb Manger service

[Service]
ExecStart=Xvfb :8 -ac -screen 0 720x1280x24

[Install]
WantedBy=multi-user.target

systemctl status app.service
Warning: The unit file, source configuration file or drop-ins of app.service changed on disk. Run 'systemctl daemon-reload' to reload units.
● app.service - Openvmi Xvfb Manger service
   Loaded: error (Reason: Exec format error)
   Active: inactive (dead)

Nov 30 16:23:36 pcl-01 systemd[1]: /lib/systemd/system/app.service:5: Executable path is not absolute: Xvfb :8 -ac -screen 0 720x1280x24

改成绝对路径

ExecStart=ip a
[Unit]
Description=Openvmi Xvfb Manger service

[Service]
ExecStart=/usr/bin/Xvfb :8 -ac -screen 0 720x1280x24

[Install]
WantedBy=multi-user.target