Eclipse “Error: Could not find or load main class”

Some time eclipse not run any java file and give exception like
"Error: Could not find or load main class"

Bellow are few solution :

Solution 1 )

• went to run configurations: - run->run configurations

      In the Classpath tab:

• Select Advanced
• Add where Eclipse usually put the *.class for the projects, which is in bin. So I added the bin directory for the project.

Solution 2)

   

• Project -> Clean will remove any existing class files and completely rebuild the project.

Solution 3)

It seems that the class is not compiled by Eclipse.
Few pointers could be-

1. Check if the .class file exists in your output folder.To know your output folder Right Click on Project->Properties->Java Build Path(Check at bottom).
2. Check if Project->build Automatically is checked in the menu.
3. Check if the HelloWorld class is in src folder or not.Right Click on Project->Properties->Java Build Path(Check source tab).