My client just sent me the base project for development purposes. I think he just zipped the project folder and sent to me.
Now when I go to NetBeans, \"New project
File >> New Project >> Java Project With Existing Source>Next >> Project Name(add a name for your project) >> Next>>Add Folder >> select your existing project source code from your Directory>>Next >> Finish
Java Project With Existing Source
You may try creating a new project in netbeans and then copy and and paste the files into it. I usually experience this problem when the project wasn't created in netbeans.