ios - iTunesConnect submission "app loads no content" with Black Screen -

i'm doing pre-release submission itunesconnect. app getting rejected , response i'm getting apple strange. app runs fine me on iphone 4s/5/5s/6/6+ if build+deploy xamarin app store build provisioning profile. when submit itunesconnect it's getting rejected , they're claiming:

we still discovered 1 or more bugs in app when reviewed on iphone running ios 8.3 on both wi-fi , cellular networks.

specifically still found app loads no content.

they supply black screenshot leads me believe app won't run them , launches , freezes on black screen. asked them more details , gave vague response didn't help. did notice screen shot appears come iphone 4s. have confirmed app store provisioned build runs on iphone 4s ios 8.3.

any suggestions? how apple running ipa submit different how xamarin deploying device? xamarin issue?

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here nsdictionary launchoptions code referred in comments

    public override bool finishedlaunching (uiapplication application, nsdictionary launchoptions)     {         // call base         base.finishedlaunching(application, launchoptions);          // handle launch options         if (launchoptions != null)         {              this.performlaunchoptions(launchoptions);         }             else         { #if use_hidestatusbar                            // hide status bar             uiapplication.sharedapplication.setstatusbarhidden(true, false); #endif              // init stuff             // call root view controller         }          return true;     }