Chaining If Else Statements system error?

[jbeltrez]

Guys I have no idea what’s going on with this lab. Heres my code:

function testSize(num) {
  // Only change code below this line
  if (num < 5) {
    return "Tiny"
  } 
  else if (num < 10) { 
    return "Small"
  } 
  else if (num < 15) { 
    return "Medium"
  } 
  else if (num < 20) { 
    return "Large"
  } 
  else {
    return "Change Me"
    }
  // Only change code above this line
}

testSize(7);```

My error: 

// running tests
TypeError: Cannot read property ‘message’ of undefined

But then theres also this message aat the top when i try to run tests: 
Something is not quite right. A report has been generated and the freeCodeCamp.org team have been notified

[JeremyLT]

I would clear your cache, restart your browser, and log back in.

Your code is mostly correct and should pass all but 2 test cases.