Port Settings for Preview

You can set the port used to serve up the preview of forms for the internal preview tabs. By default, this is set to 8888.

You can change the port if there is a conflict with another application using port 8888 on your machine.

To change the port, go to Window > Preferences > Forms Designer > Preview. If you change it to a value of 0, then an arbitrary, available port number will be used.