Frequently Asked Questions (FAQ)

The map browser isn't loading, or there is an error message or no map data when I try to view MERLIN Online. What should I do?

There can be several reasons for these issues. Make sure to verify each of the following.

• A Java Virtual Machine, or "VM" must be installed and enabled. A Java VM allows Java programs such as MERLIN Online to run. The Microsoft VM is recommended for MERLIN Online.
• MERLIN Online sends and receives data through port 4750 of your Internet connection. If your computer is located behind a corporate or large firewall, port 4750 must be opened to incoming and outgoing traffic. Your technical support or Internet Service Provider can confirm if your computer is behind a firewall, and can open the port. One common symptom of this particular problem can be that the TNTclient™ map browser opens, but the Map Selection Menu does not appear and a "Socket Exception" error message appears at the bottom of the map browser. Port 4750 must be opened for incoming and outgoing TCP traffic. Firewall software intended for home computer use (e.g. ZoneAlarm, Norton Personal Firewall or Internet Security, McAfee Firewall or Internet Security) typically does not need to be changed in order for MERLIN Online to work.
• If your computer has pop-up blocking software installed, it needs to allow pop-ups from www.mdmerlin.net and atlas.mdmerlin.net. Note that Internet Explorer 6 on Windows XP usually includes a pop-up blocker, which needs to be configured to work with MERLIN Online. MERLIN Online does not serve ads, but the site uses pop-up windows for enhanced map browsing and a more functional interface.
• MERLIN Online requires at least Internet Explorer 5.0 or Netscape 4.6, both of which were released in 1999. Most newer web browsers will work correctly with MERLIN Online.
• You may be located behind a proxy server, which may be interfering with MERLIN Online. The usual symtpom if you're behind a proxy server is the timer at the bottom of the TNTclient™ window continues to count up, but no map is ever displayed. Please contact the webmaster if this seems to be the problem.

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