You may experience a different error, the below are the most general errors you're likely to see.

Q: When I try to connect to a server, I get the error: "An Unknown Transport Related Error has Occurred."

A: This means that something is wrong with your internet connection. I have found that disconnecting and reconnecting does no good. Restart instead, then reconnect and your problem should be cleared up. One way I know this error happens is from force-quitting IE when it's in the midst of some network activity. Only rarely does it happen though. I use ramBunctious and store the IE cache in there. A sure indicator that something is wrong is when you try to delete the cache.waf file (IE's cache file) you get a message that it's in use, even if IE isn't running.
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Q. When I try to connect to a server, I get the error: "Transport address is not valid." What does this mean?

A: You are trying to connect to an address that does not exist. Verify the address you type into the Server field in the connect window.
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Q. When I try to connect to a server, I get the error: "Remote host is not responding." Why can't I connect?

A: This means that Hotline was unable to connect to a server at the address you tried to connect to. Either there is no server running at that location, or your computer was unable to reach that address. The latter could be true if you are attempting to connect from behind a firewall.
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Q. I keep getting the message "Login Failed". What's the problem?

A: The login and password you specified when connecting to the server are not valid. Verify your account information and connect again. If you tried to connect as a guest (leaving both login and password blank), then the server may not be accepting connections from guests.
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Q. I see links on web pages to Hotline Servers, but when I click them, they don't work. How do I configure my web browser to recognize these links?

A: Netscape Navigator/Communicator: Run the Setup Netscape AppleScript to configure your Netscape browser to recognize the hotline:// protocol. Note: You need AppleScript installed to do this.

Internet Explorer:
1. In Internet Explorer, go to the Preferences Window (from the Edit menu).
2. Under the Network Group, select the Protocol Helpers topic.
3. Click the Add... button.
4. Enter hotline as the protocol.
5. Click the Choose Helper... button and select the Hotline Client application.