Cannot create new virtual server

[palesths]

SYSTEM INFORMATION
OS type and version	Ubuntu Linux 20.04.6
Webmin version	2.021
Virtualmin version	7.5
Related packages	SUGGESTED

Hello
When i try to create a new virtual server i get this error:

Creating administration group tesae …
… done

Creating administration user tesae …
… failed to create administration user : useradmin::create_user failed : Failed to replace /etc/passwd with /etc/passwd.webmintmp.6002 : Operation not permitted

Fatal Error!
Failed to create virtual server : Critical feature Administration user was not properly created - Virtual server creation halted.

root@new2:~# ls -l /etc/passwd; lsattr /etc/passwd
-rw-r–r-- 1 root root 6389 Mar 30 10:49 /etc/passwd
-----a--------e----- /etc/passwd
root@new2:~#

Any ideas?

Thank you

[palesths]

Nevermind i solved it with:

chattr -a /etc/passwd
chattr -a /etc/shadow

Thank you

[tamal0007]

Hello @palesths ,
First I tried your commands:
chattr -a /etc/passwd
chattr -a /etc/shadow

it shows :
chattr: Operation not permitted while setting flags on /etc/passwd
chattr: Operation not permitted while setting flags on /etc/shadow

then I ran the below command (from above) and found :
root@server1:~# ls -l /etc/passwd; lsattr /etc/passwd
-rw-r–r-- 1 root root 7313 May 13 02:56 /etc/passwd
----ia--------e----- /etc/passwd

Then I ran :
root@server1:~# chattr -i /etc/shadow
root@server1:~# chattr -a /etc/shadow

root@server1:~# chattr -i /etc/passwd
root@server1:~# chattr -a /etc/passwd

but after a while i checked : /etc/passwd and /etc/passwd
it changed for some seconds but then reverse to previous state.
Eventually can not create new virtual server.
Would you please help me?
Thanks in advance.