I just realized I sent my client her app way too soon. I forgot that the simulator threw a SIGABRT error. Luckily, I just sent her another e-mail letting her know that her version would crash. I don't know if she's opened it yet - she hasn't let me know. The error dialog seems to suggest that the error was caused by the line of code mentioned in the title of this thread. This is strange, because the app passed the build phase with 4 warnings and no errors. The warnings are irrelevant to the issue. I have the base SDK set to 6.0, so no issues there.