error - Failed to get notificator V 5.7

Hi Xabi,
I just upgraded to version 5.9 and having the same issue. Can you please explain further steps like in which table two rows were created and how you deleted empty rows and reconfigured notifications. If you can tell commands and steps, it will be very helpful.
Thanks.

Hello Amal,

I used HeidiSQL database viewer to diagnose the problem:
https://www.heidisql.com/download.php

An empty row, linked to the failing devices, had been created in the tc_notifications table. Once the empty row was deleted, and an operational notification was reconfigured, everything started working normally:

I hope it works for you.

Hello Xabi,

I used mysql database, After removing empty row linked notificators tc_notification table, now its perfectly working for me.
Thank You

Hi Amal,
Glad it worked for you.
Regards.