If you are getting this error from systemctl "Loaded: masked (Reason: Unit hostapd.service is masked.)" we need to unmask the service.
Solution
systemctl unmask hostapd
Removed /etc/systemd/system/hostapd.service.
It's fixed
root@routerOS:/var/log# systemctl start hostapd
root@routerOS:/var/log# systemctl status hostapd
● hostapd.service - Access point and authentication server for Wi-Fi and Ethern........
iw dev wlan0 station dump
This is very useful because it is helpful if you are running something like hostapd and need to see the signal strength and negotiated connection speed.
Station ff:ff:ff:ff:ff:ff (on wlan0)
inactive time: 16309 ms
rx bytes: 25451
rx packets: 325
tx bytes: 44381
tx packets: 159
tx retries: 0
tx failed: 0
signal: -72 [-72] dBm
signal avg: -72 [-72] dBm........