Class.getName() line:640 [local variables unavailable]

When I am trying to debug a simple code, by step in or step over my test case, it throws this error “Class.getName() line:640 [local variables unavailable]”.

In my main test case I have put in one break point to call another verification class’s method (lets say A) and here is also one break point to call another class’s method (lets say B ) to delete the directory, and when I press F5 or F6 on second break point, I get above message.

I am using this java method to delete folder:
import org.apache.commons.io.FileUtils

@Keyword

public static void deleteFolder (File fileName)

{

try{

if (flagToDeleteDirectory == false)

{

FileUtils.deleteDirectory(fileName);

flagToDeleteDirectory = true;

}

}catch (FileNotFoundException e)

{e.printStackTrace();}

catch(NoSuchFileException e)

{e.printStackTrace();}

}

Please help to resolve this issue as everything seems fine after googling.

Thanks
Rafi