Lighttpd

I configured lighttpd/1.4.55 (ssl) for webdav on Ubuntu 20.04 LTS server.
I can connect via webdav to the server from a linux computer, everything works fine.
I can connect via webdav to the server from a Windows 10 computer, everything works fine.
But I can't connect via webdav to the server from a Windows 7 SP1 x64 computer, NOT work.
But I can connect to any other Webdav server using this windows 7 SP1 x64 computer.

I can't find out where the problem is? Why it doesn't work lighttpd webdav on windows 7 SP1 x64?

/etc/lighttpd/lighttpd.conf:

server.modules = (
        "mod_indexfile",
        "mod_access",
        "mod_alias",
        "mod_redirect",
)

server.document-root        = "/var/www/html" 
server.upload-dirs          = ( "/var/cache/lighttpd/uploads" )
server.errorlog             = "/var/log/lighttpd/error.log" 
server.pid-file             = "/run/lighttpd.pid" 
server.username             = "www-data" 
server.groupname            = "www-data" 
server.port                 = 80

server.http-parseopts = (
  "header-strict"           => "enable",# default
  "host-strict"             => "enable",# default
  "host-normalize"          => "enable",# default
  "url-normalize-unreserved"=> "enable",# recommended highly
  "url-normalize-required"  => "enable",# recommended
  "url-ctrls-reject"        => "enable",# recommended
  "url-path-2f-decode"      => "enable",# recommended highly (unless breaks app)
  "url-path-dotseg-remove"  => "enable",# recommended highly (unless breaks app)
)

index-file.names            = ( "index.php", "index.html" )
url.access-deny             = ( "~", ".inc" )
static-file.exclude-extensions = ( ".php", ".pl", ".fcgi" )

compress.cache-dir          = "/var/cache/lighttpd/compress/" 
compress.filetype           = ( "application/javascript", "text/css", "text/html", "text/plain" )

include_shell "/usr/share/lighttpd/create-mime.conf.pl" 
include "/etc/lighttpd/conf-enabled/*.conf" 

server.modules += (
        "mod_compress",
        "mod_dirlisting",
        "mod_staticfile",
)

$HTTP["host"] == "10.20.30.40:443" {
    server.document-root = "/var/www/html" 
    alias.url            = ( "/webdav" => "/var/www/webdav" )
    $HTTP["url"] =~ "^/webdav($|/)" {
    dir-listing.activate = "enable" 
    webdav.activate      = "enable" 
    webdav.is-readonly   = "disable" 
    auth.backend         = "htpasswd" 
    auth.backend.htpasswd.userfile = "/etc/lighttpd/passwd.dav" 
    auth.require         = ( "" => ( "method"  => "basic",
                                     "realm"   => "webdav",
                                     "require" => "valid-user" ) )
  }
}

enabled after installation:
lighty-enable-mod auth
lighty-enable-mod webdav
lighty-enable-mod ssl

inside the file:
/etc/lighttpd/conf-enabled/05-auth.conf:

server.modules                += ( "mod_auth" )

/etc/lighttpd/conf-enabled/10-ssl.conf:

server.modules += ( "mod_openssl" )

$SERVER["socket"] == "0.0.0.0:443" {
        ssl.engine  = "enable" 
        ssl.pemfile = "/etc/lighttpd/webdav.pem" 
        ssl.cipher-list = "HIGH" 
}

/etc/lighttpd/conf-enabled/10-webdav.conf:

server.modules += ( "mod_webdav" )
webdav.sqlite-db-name = "/var/cache/lighttpd/lighttpd.webdav.db" 

/var/log/lighttpd/error.log:

2020-05-06 00:02:13: (server.c.1970) server stopped by UID = 0 PID = 1
2020-05-06 00:02:14: (server.c.1488) server started (lighttpd/1.4.55)
2020-05-06 00:02:56: (mod_openssl.c.1762) SSL: -1 5 104 Connection reset by peer
2020-05-06 00:02:56: (mod_openssl.c.1762) SSL: -1 5 104 Connection reset by peer
2020-05-06 00:25:09: (mod_openssl.c.1762) SSL: -1 5 104 Connection reset by peer
2020-05-06 00:25:09: (mod_openssl.c.1762) SSL: -1 5 104 Connection reset by peer

in the windows console when connecting:

> net use w: https://10.20.30.40:443/webdav /PERSISTENT:NO /USER:minik PasSwOrd

System error 67.
The network name cannot be found.