Router cannot reboot after AdguardHome installation

I used OpenWRT on Redmi AC2100. I follow the instructions and set up the Adguardhome. However, it does not open with the reboot of the router, so I edit /etc/rc.local
Command: nano /etc/rc.local and add /opt/AdGuardHome/AdGuardHome (then save and exit)
The AdguardHome opened with the reboot of the router. However, the router led light on the router (system led) turned to RED (instead of blue) and the router cannot be rebooted from CLI or OpenWRT. I remove the line /opt/AdGuardHome/AdGuardHome in /etc/rc.local and unplugged the device. Then everything works normally. How this happens?