Random crashes occur in my iphone project, see two call stacks, all in web core, all crash after UIWebView deallocate <p>Random crashes occur in my iphone project, see two call stacks, all in web core, all crash after UIWebView deallocate. </p> <p>See crash 1, seems web core can't close it completely, is it blocked by other running threads? </p> <p>See crash 2, why it is still dealing with some issues even if UIWebView has been released? </p> <p>Any idea or discussion will be appreciated, thanks in advance. </p> <p>Crash 2 has higher reproducible rate than crash 1, scan WebCore source code, it seems be manifest cache has been deleted (who did it?) when try to access it. </p> <p><img src="https://i.stack.imgur.com/iyHo9.png" alt="web core crash 1"></p> <p><img src="https://i.stack.imgur.com/SYicM.png" alt="web core crash 2"></p>