Crash while using ADEumInstrumentation in iOS

I am trying to use AppDynamics mobile SDK. I install it using CocoaPods using 

pod 'AppDynamicsAgent'

In my AppDelegate.m in didFinishLaunchingWithOptions I specify

    [ADEumInstrumentation initWithKey:@"XX-XXX-XXX-XXX" enableLogging:YES];

Inside my ViewController I have a call to

    [ADEumInstrumentation startTimerWithName:@"QUERY"];    [ADEumInstrumentation stopTimerWithName:@"QUERY"];

My Application crashes whenever it executes startTimerWithName. The log I see is

Agent added server correlation header to request.
2015-11-30 12:21:11:324 AppName[28314:70b] Agent release version 4.1.5.0
2015-11-30 12:21:11:324 AppName[28314:70b] Agent actual configuration:
Application Key: XX-XXX-XXX-XXX
Collector URL: https://mobile.eum-appdynamics.com
Log level: -1
Features:
{
    Breadcrumbs = 1;
    "Crash Reporting" = 1;
    Instrumentation = 1;
}
2015-11-30 12:21:11:325 AppName[28314:70b] Agent using executable UUID: xxxxx

Please help me what is going wrong here.