When running against iOS 8, I began to see the following exception coming from the deep bowels of UIWebView:
[WebActionDisablingCALayerDelega
As @André Morujão answered, removing -webkit-overflow-scrolling:touch; from the scrolling element stops the exception. But I found that the exception was only happening when I added display:none css to the scrolling element.
Edit: I was able to continue using display:none to hide my scrolling element by putting -webkit-overflow-scrolling:touch; inside of its own class .scroll and using jquery to add and remove that class from my scrolling element before and after hiding it: