Here are some of the more common error codes and descriptions of the errors, that a user might come across.

Basically, the error codes in the 400 and 500 range are the codes that are most common to the end user:

The 400 codes are intended for cases in which the client (Mosaic, Netscape, etc) seems to have caused some sort of problem when asking the server for a html document.

The 500 codes are intended for instances when the Server software (NCSA HTTPD, Netsite, etc.) running on the site that you are contacting is having a problem sending you the html document.

Bad request 400:
This is a fairly common error and basically means that the requested document could not be sent because of syntax error in the URL (site address).

Unauthorized 401:
This is one of the most common error messages and usually means that the Server is expecting some sort of encryption id from the browser (Mosaic, Netscape, etc) and when it does not recieve it, the server issues an error message.

Forbidden 403:
The document you are requesting is "forbidden" meaning that you do not have read privlidges or are not allowed to have the page sent to you.

Not found 404:
This is the most common and is similar to the 400 error. Basically this means that the document you have requested no longer exsists or that the URL (site address) is incorrect.

Internal Error 500:
The server was unable to send the html document to you due to an internal (server software) error.

Not implemented 501:
This error occurs when for example, you have pressed the submit button on a form. The server replys with this error message because it dosen't support the feature that you have requested. This is not a real common error, but typically occurs when new features or forms are implemented.

Service temporarily overloaded 502:
The server cannot process the request due to a high load (whether HTTP servicing or other requests from users). Basically, this is the "if at first you don't suceed..." error. The solution is to try back later at a time when net load or server traffic is lower. Gateway timeout 503:
This error is caused by the connection timing out, either due to server problems, net problems or client problems. Basically, the request for information stops because the pathway to the web server has been closed.

Some other common errors that can occur in Netscape are:

1. A windows pops up with:

 

 

"Netscape is unable to locate the server: (server name) The server dose not have a DNS entry.

 Check the server name in the location (URL) and try again."
 
 

Basically, Netscape is telling you that the server name is incorrect and that it can't locate the computer you want to get to on the Internet.
 
 
2. A window pops up with:

 

 

"Netscape's network connection was refused by the server: (server name)
The server may not be accepting connections or may be busy.
Try connecting again later"
 
  This is a really common error when trying to connect to a busy FTP software site, such as Netscape's. Because the server you are trying to connect to is not a web server and can't issue any of the above error messages, the browser software issues this error message. Basically, the only thing that you can do is try again later.
 
 
3. Another common error is :

 

 

News Error:
News host responded: No such group
 
  or Cannot locate host
 
  or
 
  Cannot Talk
 
  This means that you most likely do not have your news server set properly in your WWW browser configuration. Please see your browser documentation on how to set this option. If you do not know what news server you should be connecting to, you'll need to ask your internet provider. It may also mean that the Usenet server you are using does not support the news group that you requested.