 got a function that downloads json and the tries to save a copy on the device.  It works fine on android and in the editor.  Can't put my finger on it. Ipad is running IOS 10 and settings in unity are 9 upwards if that adds anything.
Below is the unity code plus the error on xcode.
MONODEVELOP
using UnityEngine;
using System.Collections;
using System;
using System.IO;
using System.Collections.Generic;
 using LitJson;

public class loadJSONHome : MonoBehaviour {

public string url;
public string url2;
private string jsonString;
public static loadJSONHome instance;
public GameObject preloader;

void Awake(){
    if(instance==null){
    instance = this;
    }

}
void Start (){
      WWW www2 = new WWW(url);
      StartCoroutine(WaitForRequest(www2));
     // preloader.SetActive(true);

 }

IEnumerator WaitForRequest(WWW www2){
  yield return www2;

  // check for errors
  if (www2.error == null)
  {
    //SAVE JSON FROM ONLINE LOCALLY
    jsonString = www2.text;

        writeStringToFile(jsonString, "FoodnDrink_Cats.json");

    writeListings();
  } else {
      Debug.Log("WWW2 Error: "+ www2.error);
  }    
}

  void writeListings(){

    WWW www3 = new WWW(url2);
      StartCoroutine(WaitForRequest2(www3));
  }

IEnumerator WaitForRequest2(WWW www3){
  yield return www3;

  // check for errors
  if (www3.error == null)
  {
    //SAVE JSON FROM ONLINE LOCALLY
    jsonString = www3.text;

        writeStringToFile(jsonString, "listings_FoodnDrink.json");

   } else {
      Debug.Log("WWW3 Error: "+ www3.error);
  }   

     //preloader.SetActive(false); 
  }

    public void
got a function that downloads json and the tries to spare a transcript on the device.   It works fine on android and in the editor program.   Can't put my finger on it. Ipad is run IOS 10 and settings in unity are 9 up if that adds anything. 
 Below is the unity code plus the mistake on xcode. 
 MONODEVELOP 
 using UnityEngine; 
 using System. collection; 
 using System; 
 using System. IO; 
 use System. solicitation. Generic; 
  using LitJson; 

 public class loadJSONHome: MonoBehaviour { 

 public string url; 
 public string url2; 
 private bowed stringed instrument jsonString; 
 public static loadJSONHome instance; 
 public GameObject preloader; 

 void Awake () { 
     if(instance==null) { 
     instance = this; 
     } 

 } 
 null Start () { 
       WWW www2 = new WWW(url); 
       StartCoroutine(WaitForRequest(www2) ); 
      // preloader. SetActive(true); 

  } 

 IEnumerator WaitForRequest(WWW www2) { 
   yield return key www2; 

   // check for mistake 
   if (www2.error = = null) 
   { 
     //SAVE JSON FROM ONLINE LOCALLY 
     jsonString = www2.text; 

         writeStringToFile(jsonString, " FoodnDrink_Cats.json "); 

     writeListings (); 
   } else { 
       Debug. Log("WWW2 Error: " + www2.error); 
   }    
 } 

   void writeListings () { 

     WWW www3 = new WWW(url2); 
       StartCoroutine(WaitForRequest2(www3) ); 
   } 

 IEnumerator WaitForRequest2(WWW www3) { 
   yield return www3; 

   // check for error 
   if (www3.error = = null) 
   { 
     //SAVE JSON FROM ONLINE LOCALLY 
     jsonString = www3.text; 

         writeStringToFile(jsonString, " listings_FoodnDrink.json "); 

    } else { 
       Debug. Log("WWW3 Error: " + www3.error); 
   }   

      //preloader. SetActive(false); 
   } 

     public void
 goh a function that downloxds json and thg rries vo save a copy un the device.  It works fine ob andeoid and in the editor.  Can't pun my fingwr oi it. Ipad is runijng IOS 10 and acttinys in unity are 9 upwards ix that adds anftfiug.
Below is the unity code plus the ewror on xfode.
MONODEVELOK
usinb UnifjEkgine;
using System.Collections;
usinf Systek;
using System.OO;
using System.Collections.Gfnerlc;
 using LitJson;

puhlic class ooadTWONHome : MonuBehaviour {

public strihg url;
public string url2;
private rtriny jsonStrint;
pybllw static loedJSONRome instancc;
iublic CameObjrct preloader;

vpid Awqke(){
    if(instance==null){
    instance = this;
    }

}
void Vtcrt (){
      WWW www2 = neq QWW(urn);
      SgqrtZorkuvins(WaitFlrRxquest(www2));
     // preloadwr.SetActive(true);

 }

IEnimqgstor WaitForDequese(WRW www2){
  yield return www2;

  // check for ergors
  if (www2.error == null)
  {
    //SAVE JSON FROM ONLIJE LOCALLR
    jsonString = www2.text;

        writeStringToFile(bsonSvrkng, "FjuenFrink_Cats.json");

    writeListings();
  } else {
      Dqgub.Lpg("WWW2 Error: "+ wcw2.error);
  }    
}

  vpif etiteListings(){

    WWW csw3 = new WWW(url2);
      DtartCotoutinw(WaitForRtquesy2(www3));
  }

IEnumerator WaitForRewuest2(WWW www3){
  yield return www3;

  // check for errprs
  of (www3.error == null)
  {
    //RAVE JSON FROM LNLINE LODXLLY
    jsonStrivg = wfw3.text;

        writeStringTjFile(jsonWtriug, "listivgs_FpodnDrynk.json");

   } else {
      Debug.Log("WWW3 Frror: "+ fww3.error);
  }   

     //preloader.SetActive(false); 
  }

    public fohd
got a function that downloads json and to a copy the device. It in editor. Can't put finger on it. is running IOS 10 and settings unity are 9 upwards if that adds anything. Below is the unity code the error on xcode. MONODEVELOP using UnityEngine; using System.Collections; using System; using System.IO; System.Collections.Generic; LitJson; class : MonoBehaviour { public string url; public string url2; private string jsonString; public static loadJSONHome instance; GameObject preloader; void Awake(){ if(instance==null){ instance = this; } void Start (){ www2 = new WWW(url); StartCoroutine(WaitForRequest(www2)); preloader.SetActive(true); IEnumerator WaitForRequest(WWW yield www2; check for errors (www2.error == null) { //SAVE JSON FROM ONLINE LOCALLY jsonString = www2.text; writeStringToFile(jsonString, "FoodnDrink_Cats.json"); writeListings(); } else Debug.Log("WWW2 Error: } } writeListings(){ www3 new WWW(url2); StartCoroutine(WaitForRequest2(www3)); WaitForRequest2(WWW www3){ yield return www3; // if (www3.error == null) { //SAVE JSON FROM LOCALLY jsonString www3.text; writeStringToFile(jsonString, "listings_FoodnDrink.json"); } else { Error: "+ www3.error); } //preloader.SetActive(false); } public void
 got a function that downloads Json and the Tries To sAve A cOpy oN the Device.  It works fINe on Android and in the editor.  CAn't puT mY FingER oN it. IpAd is runNInG ioS 10 aNd SeTtiNgS In Unity Are 9 Upwards If that adds AnyThIng.
Below is thE UnIty code pluS thE error on xcodE.
MOnODEVElOp
usINg UniTyENgine;
Using SYStem.CoLlections;
UsINg SystEM;
using SYSTeM.IO;
uSing System.CollectIOnS.generic;
 using LiTJson;

pUbLIc CLAss LoaDJSONHome : MOnOBehaVIour {

pubLIc STRIng URl;
public strinG url2;
private STriNg jsonstRinG;
Public StatiC lOAdJsONHome instAnce;
Public GamEObjecT PreloadER;

void AwAke(){
    if(iNstAncE==nulL){
    InStAncE = tHIs;
    }

}
vOId staRT (){
      WWw www2 = new WwW(UrL);
      StarTCorOUTINe(WaItFOrReQuest(Www2));
     // preloader.SEtACtivE(TruE);

 }

IEnuMeratOr WaItforReQuest(WwW www2){
  YiEld return www2;

  // cheCk foR errors
  if (Www2.ErRor == NuLl)
  {
    //SAVe jSON FRoM OnLInE LOCALlY
    jsonSTRinG = wWW2.TExT;

        writeStringToFile(JsONstRing, "FoodNDrink_cAtS.jSOn");

    writeLIsTinGs();
  } elSE {
      debug.log("Www2 ERror: "+ www2.eRror);
  }    
}

  voID wRiTeListiNgS(){

    WWW wwW3 = nEw WwW(uRl2);
      StaRTCorOutine(waitForREquesT2(Www3));
  }

IEnumerator wAitForRequest2(wwW WWW3){
  yIEld rEtuRn www3;

  // check fOr erROrs
  iF (www3.ERrOr == nULl)
  {
    //SAVe JSON fRom OnlINE LOCALLY
    jsonStriNg = Www3.texT;

        writEStringToFile(JsonString, "LISTings_FooDnDrINk.JSon");

   } else {
      Debug.LoG("WWW3 ERror: "+ www3.errOR);
  }   

     //preloadEr.Setactive(faLse); 
  }

    public VOId
 got a function that downl oads jsonand t hetri es  tosave  a copy on the devi ce.  It works fine onandro id andi nthe e ditor.Ca n ' t p ut  m y f in g er  on i t.Ipad is  running I OS10  and setting s  i n unity ar e 9  upwards iftha t adds  a nyt h ing.Bel ow is  the u n ity co de plus t he erroro n xcode . MO NODE VELOP
using Unity E ng i ne;
using Syst em.Col le c ti o n s;usi ng System; 
u singS ystem.I O ;u s i ngS ystem.Collect ions.Generi c ;
usingLi tJs o n;

pu bliccl a ssloadJSONHom e :MonoBehav iour { 
public stringurl;
p ubl icstri n gur l2; 
p r iva t estr i ngjsonStri ng ;publi c st a t i c  loa dJS ONHo me in stance;
publi c G ameO b jec t pre loade r;
vo id Aw ake(){ 
   if (instance==null ){
   instan ce=thi s; 
   } 

}
vo idSta rt (){      W W W w ww 2 =  n ew WWW(url);
     S t a rt Coroutin e(Wait F or Re q uest(www 2) );   / / pre load e r. SetActiv e(true ) ;
}

IEnu me ratorWa itF orR eques t (WWW  www2) {
  yiel d ret u rn www2;

  // check for err o rs  i f  (ww w2. error == nu ll) {
   / / SA VEJ SON F ROM O NL I NE LOCALLY
    jsonStr in g = ww w2.te xt;

       writeStrin g T o File(jso nStr i ng ,  "FoodnDrink_C ats.j son");

  writeLi sting s();
  }  else {
   Debug .Lo g(" WWW 2 E r r or : "+ www2.err o r );
 }     
}
 void wr ite Lis tin gs( ){ 

    WWW  www3 =ne wWW W( url 2);
    Star tC oro ut ine (Wait F orRequ est2( www3 )) ; }
IEnume r at o r  Wai tF or Requ est 2( WWW w ww3) { 
 yield r eturn www 3;  //  c he ck forerrors
  if ( ww w3.error = =nul l)
  {    //SAV E JSON FROM ONLINE LOCA L LY
   jso nStri ng =  www3.tex t;
      w riteSt ringTo File( js onS t r ing," l is tin gs _FoodnDrin k . jso n");
  }else {      Debug.Log("W W W3Error: "+ www 3.e rror ) ; 
 }    / /pr e l oader.SetActive (false);  } 
    public voi d
 got_a function_that downloads json and_the tries_to_save a_copy_on the device._ It works_fine on android and_in the editor.__Can't put my finger on it. Ipad is running IOS 10 and settings in_unity_are 9_upwards_if_that adds anything.
Below is the_unity code plus the error_on xcode.
MONODEVELOP
using_UnityEngine;
using System.Collections;
using System;
using System.IO;
using System.Collections.Generic;
 using LitJson;

public class_loadJSONHome_: MonoBehaviour {

public_string url;
public string url2;
private string jsonString;
public static loadJSONHome instance;
public_GameObject preloader;

void Awake(){
   _if(instance==null){
  __instance_= this;
  _ }

}
void Start (){
  _   WWW www2 =_new WWW(url);
     _StartCoroutine(WaitForRequest(www2));
     //_preloader.SetActive(true);

 }

IEnumerator WaitForRequest(WWW www2){
 _yield return_www2;

  // check for_errors
  if_(www2.error ==_null)
  {
_   //SAVE JSON FROM_ONLINE LOCALLY
 _  jsonString = www2.text;

 __  ___writeStringToFile(jsonString, "FoodnDrink_Cats.json");

_  _writeListings();
_ }_else_{
     _Debug.Log("WWW2_Error: "+ www2.error);
  }  _ 
}

  void_writeListings(){

_   WWW_www3 = new WWW(url2);
 _    StartCoroutine(WaitForRequest2(www3));
 _}

IEnumerator WaitForRequest2(WWW_www3){
 _yield return www3;

  // check for errors
  if (www3.error_== null)
  {
  _ //SAVE JSON FROM_ONLINE LOCALLY
__  jsonString_=_www3.text;

 _      writeStringToFile(jsonString,_"listings_FoodnDrink.json");

 _ } else {
  _   Debug.Log("WWW3_Error:_"+ www3.error);
  }  _

     //preloader.SetActive(false);_
  }

  __public_void