Issue DNSSEC issue

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Unable to sign domains with the DNSSEC.
Ubuntu 16.04.6 LTS
Plesk Obsidian: Version 18.0.21 Update #5
Plesk DNSSEC: 1.2.3-93

Error: Unable to sign the DNS zone. Execution CLI utility is failed: dnsmng. dnsmng: /usr/sbin/dnssec-keygen failed with code 1.
Stdout:
Stderr:dnssec-keygen: fatal: The -r option has been deprecated.
System random data is always used.

System error 11: Resource temporarily unavailable dnsmng: /usr/sbin/dnssec-keygen failed with code 1.
Stdout:
Stderr:dnssec-keygen: fatal: The -r option has been deprecated.
System random data is always used.

System error 11: Resource temporarily unavailable

Tried to reinstall DNSSEC but issue is the same.
Also DNSSEC records were removed. (facepalm).