When running against iOS 8, I began to see the following exception coming from the deep bowels of UIWebView
:
[WebActionDisablingCALayerDelega
Use WKWebView instead of UIWebView. (it was first included in iOS 8). I've tried it, and seems that it hasn't got this bug. Also, it may improve the performance compared with it predecessor. Seems likely that Apple will make the de-facto standard in the near future, if not now. It has interfaces and delegates somewhat similar to UIWebView. Definitively worth a try.
If you are targeting pre-iOS 8, you can implement fallback procedures to load either UIWebView or WKWebView, here you are an out-of-the-box implementation