java.lang.NoClassDefFoundError on NetBeans

I was using NetBeans when I accidentally clicked on a hammer icon with a broom, the equivalent of pressing Mayus + F11 (clean and build project) is what it puts me.

When doing it when I try to execute the program I get the following error:

    Exception in thread "main" java.lang.NoClassDefFoundError: com/manuelsagra/laxtore/utils/FileUtils
    at com.manuelsagra.laxtore.App.main(App.java:76)
Caused by: java.lang.ClassNotFoundException: com.manuelsagra.laxtore.utils.FileUtils
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

He tells me that the class is not there, when it is. I do not know what to do. The undo button has not helped me, and I do not understand where the error comes from.