Apache Server Admin no longer working

[Ute Hoffmann]

Hallo,
I got a Mac OS X 10.4.x Server machine. On this machine we have defined 
a number of virtual hosts. From a certain day on the Webserver Admin 
Tool would no longer show the virtual hosts (or any sites).

The sites run all as expected, going into terminal and putting in: 
apachectl configtest I get Syntax ok, but as apache is up and running 
as expected, this seems logical.

That was changed by me in terminal:
- I inserted the webobjects module in from of the rewrite module in the 
httpd.conf file. The modules are al shown correctly in WebServer Apache 
Admin-Tool, so I assume this is not part of the problem.

- I inserted into some of the virtual hosts a rewrite directive in 
terminal (as I saw no way to insert it via Server Admin tool. I have 
another machine (Xserver) running, also Mac OS X 10.4.x and I have 
exactly the same configuration there and ... I can see all virtual 
hosts in the server admin tool. I checked the config files for the 
virtual hosts in both servers and they have the same structure and the 
rewrite part I entered via terminal in both servers are identical (have 
identcal structure).

Now: I thought it would help to try to create a new virtual host on the 
server, where no virtual hosts are shown any more via Server Admin Tool.

The new virthost could not be saved. Error: The error page must be 
defined. I did define a error page in the new vitrual host. I did 
define a error page in all existing virtual hosts. There is no general 
error-page defined in httpd.conf, but this is so in both servers, the 
one where the server admin tool shows the virtual hosts and in the on 
where no virtual hosts are seen...

The only difference I can see is this:

Working server virtual_host_global.conf
Listen IP:443
NameVirtualHost IP:443
Listen IP:16080
NameVirtualHost IP:16080

  virtual_host_global.conf  on Server not showing virtual hosts:
Listen IP:80
NameVirtualHost IP:80


Suppose the IP is correct in both servers. Can someone comment on this 
or has an idea where to look for the problem next, or whether the  
difference in virtual_host_global.conf could be part/the problem?

Thanks a lot for your help. I have to get this working again (not for 
my use, I'm happy with terminal) but for someone else, who needs it.

Regards,
Ute