Unable to find [classname] which you specified as the [launcher's] Main classname.

Message
Unable to find [classname] which you specified as the [launcher's] Main classname. Be sure that it's inside a JAR that you are distributing.

 

Comments
You defined a launcher for a java application with a main classname.

Ignore this message if you're confident that the classname is inside a JAR or zip file which you've included in this project. Otherwise, change the classname for the launcher or add the appropriate JAR file to the Select Files panel.