App crashing with iOS 7.1.1?

Over the past couple weeks, we have had a number of users email us and tell us that our app won’t even launch on their iOS 7.1.1 device any more. Has anyone seen this? We have not been able to duplicate teh issues internally with our iOS 7.1.1 updated devices. But from what our customer tells us, it sounds like the Splash screen shows up briefly before our app crashes. It appears to be iOS 7.1.1 specific and happens across a range of devices (we’ve heard iPhone 4S, iPhone5, etc).

We are at a complete loss, and haven’t been able to find relevant stuff online. Would love to see if anyone else has encountered this.

Thanks!

Andrew