Logged In: NO

You do not need the source files. Most likely you are not
including the LiquidLnF.jar file as a resource in your JNLP
file. If you do not, then the jar file will not be pulled
down to the client, therefore, your L&F call to set it to
Liquid will fail gracefully and the default will be used.
(Either System or CrossPlatform depending on the client's
JRE version)

Make sure you have the LiquidLnF.jar file specified as a
resource in your JNLP file.