java - implicit super constructor object() is undefined. must explicitly invoke another constructor -

Is this a new bug? I got a new Mac computer and the checksum matches exactly but when I try to make a simple class, just for basic testing, I get the error mentioned in the headline I never complained about java Object () Constructor here is the square:

  package com.my.ok; Public class first {}   
 Edit:  
 I think if I type  execution environment  to  javaSE- 1.7   
    
 
 
 This problem occurs if your  JRE  project  is not configured in the built path.  <
    
 
   
  Build Path  - & gt; Select  Configure Build Path   
 Go to  Library tab   Add Library .  
 Select  JRE System Library  Click  Next   
 Then from the option according to your requirement  JRE  Right click on the project and select  end    
 Properties   / Code>.  
 Select  Java platform in the Library category  according to your requirement  
 Then go to Source category and select  Source / Binary format  and select your Choose JDK as per the requirement. The error was because you did not include the system library in your project and your class  object ()  was not able to find the constructor, which is said earlier in the hierarchy when you are creating a thing when you create an object.  
 Example:  
  package com.my.ok; Public class first {}   
 what happens  compiler  by default your  first  class to  object  class Expands to  
  package com.my.ok; The public class extends first object {}   
 but in your case the  object  class was not found and you are getting this error.