Cannot load component class

Question

Cannot load component class scroll.ScrollPane from project C:\Users\USER\Document\NetBeansProjects\Coba1-Tubes-Algo2
The Class could not be found. Note the class must be compiled and must be part of the source or dependencies of the project where the target GUI form belongs to.

Here is the ScrollPane code
https://code.sololearn.com/cWnfWmeLgn2a/?ref=app

Here is my jframe

https://code.sololearn.com/cXm48W9RM8CB/?ref=app

Answer 1

This may be a Netbeans bug. Try searching Google for the error message. Obviously we cannot reproduce your issue here on Sololearn even if you share your complete project (which you didn't).

Are you using the latest version of Netbeans?
Did you change your Java version during the project?

You should look around online for some more tips.

https://stackoverflow.com/questions/16202054/netbeans-cannot-add-custom-jpanel-in-swing-editor

https://www.techyv.com/questions/error-loading-component-jframe-panel-java-netbeans/

https://bz.apache.org/netbeans/show_bug.cgi?id=201747

Answer 2

Tibor Santa But, I tried to click build project, then tried again and it worked

It seems the problem is that I didn't build the project first?

Do you have to build the project first before making a design?

I don't understand

Answer 3

Nasywa I am not familiar with the intricacies of Netbeans. No matter how it tries to hide the complexity of the development tools from you, you should still be aware what happens behind the scenes. Java is a compiled language. Compilation means that the JDK transforms your Java code to JVM bytecode, which can then be executed by the runtime, the Java Virtual Machine. Your program can have many parts and dependencies on other libraries, and during compilation all these links and related code are explored and added to the bytecode. This is what "Build Project" does, I suppose.