The Greenbone Vulnerability Manager service is not responding on Kali Linux OS

GVM versions

gsad: (‘gsad --version’) GSAD version 21.4.2
gvmd: (‘gvmd --version’) Greenbone Vulnerability Manager version 21.4.3

Environment

Operating system: Kali GNU/Linux Rolling 2021.3
Kernel: (‘uname -a’) Linux kali 5.10.0-kali7-amd64 #1 SMP Debian 5.10.28-1kali1 (2021-04-12) x86_64 GNU/Linux
Installation method / source: virtual machine from kali portal

Hello Gents,

Please, may I ask your help about below error mesage:

The Greenbone Vulnerability Manager service is not responding. This could be due to system maintenance. Please try again later, check the system status, or contact your system administrator.

Many thanks in advance!