Crash when auto updating from google sheets on iOS

NullReferenceException: Object reference not set to an instance of an object.
  at I2.Loc.LanguageSourceData+<Import_Google_Coroutine>d__65.MoveNext () [0x00000] in <00000000000000000000000000000000>:0 
  at UnityEngine.SetupCoroutine.InvokeMoveNext (System.Collections.IEnumerator enumerator, System.IntPtr returnValueAddress) [0x00000] in <00000000000000000000000000000000>:0 

2022-01-19 19:43:34.135685+0300 Thousand[1581:197266] [YandexMobileMetrica] Error event is received: NullReferenceException: Object reference not set to an instance of an object.. (apiKey: fb1d31de-xxxx-xxxx-xxxx-xxxxxxxx4af1).
NullReferenceException: Object reference not set to an instance of an object.
  at I2.Loc.LanguageSourceData+<Import_Google_Coroutine>d__65.MoveNext () [0x00000] in <00000000000000000000000000000000>:0 
  at UnityEngine.SetupCoroutine.InvokeMoveNext (System.Collections.IEnumerator enumerator, System.IntPtr returnValueAddress) [0x00000] in <00000000000000000000000000000000>:0 
UnityEngine.UnhandledExceptionHandler:PrintException(String, Exception)
UnityEngine.UnhandledExceptionHandler:HandleUnhandledException(Object, UnhandledExceptionEventArgs)

IEnumerator Import_Google_Coroutine(bool JustCheck)
{
  UnityWebRequest www = Import_Google_CreateWWWcall(false, JustCheck);
  if (www==null)
    yield break;

  while (!www.isDone)
    yield return null;

  //Debug.Log ("Google Result: " + www.text);
  bool notError = string.IsNullOrEmpty(www.error);
  string wwwText = null;

  if (notError)
  {
    var bytes = www.downloadHandler.data;
    wwwText = Encoding.UTF8.GetString(bytes, 0, bytes.Length); // <<<<<<<<<<<<<<<< NULL REFERENCE ERRROR IS HERE

    bool isEmpty = string.IsNullOrEmpty(wwwText) || wwwText == "\"\"";
...