On Plesk server DNS role was removed by the administrator via Server Manager. As a result, domains for which it serves as a master DNS server cannot be resolved.
The server cannot serve DNS without proper role installed on it.
Install the DNS role back on the Plesk server, via Server Manager or any other more suitable way. If the domains do not start working after that, please follow the next step.
Rebuild DNS configuration on the Plesk server with this command:
> cd %plesk_bin% > dnsmng.exe update *
It will build new DNS configuration files based on what is stored in Plesk database.