One of the following two possibilities might have caused the problem:

• The file and Marvin are not on the same server. From security reasons, Java applets can only access files from their host web site.
• You are behind a firewall which does not proxy DNS correctly or at all. Netscape Navigator 4.01 and later versions do not trust in such misconfigured proxies by default, so applets cannot connect back to their host web site.

There are two ways to solve the firewall problem:

1. Ask the system administrator of your intranet to reconfigure the firewall correctly, or

2. Modify Netscape's preferences "manually" by editing your Preferences file.

The name and location of this file varies from platform to platform:

Macintosh:	System Folder:Preferences:Netscape f:Netscape Preferences
UNIX:	~/.netscape/preferences.js
Windows:	\Program Files\Netscape\Users\<username>\prefs.js

To enable the preference, add this line to the Preferences file:

user_pref("security.lower_java_network_security_by_trusting_proxies",true);