Explanation: Some other process (Apache, IIS, Skype, another SQL Anywhere engine, etc) is already using TCP/IP port 80.

Either tell that process to stop using port 80 or tell Foxhound to use a different port.

For example, to stop Skype from using port 80:

• Open the Skype window,

• click on Tools - Connection options...

• uncheck the "Use port 80 and 443 as an alternatives for incoming connections" option,

• click on Save button and

• restart Skype to make the change effective.

See also...
What HTTP port should I use for Foxhound?
How do I tell Foxhound to use an HTTP port other than 80?
IANA port number assignments
Database server shutdown due to startup error