Netbeans - Error: Could not find or load main class

So I'm making a java application in Neatbeans 7.4, been working at it for a while, everything was fine, running the project worked fine, but now when I hit run project, I get the error

Error: Could not find or load main class phleveledit.MainWindow
Java Result: 1
BUILD SUCCESSFUL (total time: 0 seconds)

I can't think of what I did right before this started happening, so I don't know what I should change.. The code doesn't appear to have any errors. Here's a screenshot of the IDE+project folder

Image (http://puu.sh/5ldYB) :

Any ideas?

Edit: Unfortunately I happened to fix this problem by removing some code, which probably had some errors Netbeans couldn't detect, but I don't know what was exactly wrong so can't vote on a correct answer.

Solution 1:

1. Right click on your Project in the project explorer
2. Click on properties
3. Click on Run
4. Make sure your Main Class is the one you want to be the entry point. (Make sure to use the fully qualified name i.e. mypackage.MyClass)
5. Click OK.
6. Clean an build your project
7. Run Project :)

If you just want to run the file, right click on the class from the package explorer, and click Run File, or (Alt + R, F), or (Shift + F6)

Solution 2:

Just close the Netbeans. Go to C:\Users\YOUR_PC_NAME\AppData\Local\Netbeans and delete the Cache folder. The open the Netbeans again and run the project. It works like magic for me.

(AppData folder might be hidden probably, if so, you need to make it appear in Folder Options).

Solution 3:

You can :

• RightClick on project node and go to Set configuration
• Select the main class for your application.
• Then clean and build.

Even if the above steps don't work for you then then delete the Netbeans cache by deleting the (index) folder

User\.netbeans\SOME_NUMBER_reflecting_your_version\var\cache\index\

Solution 4:

Sometimes due to out of memory space error, NetBeans does not load or find main class.

If you have tried setting the properties and still it is not working then try

1. Select the project from the project explorer
2. Click on Run in the Menu Bar
3. Click on Compile

It worked for me.