sandboxd Notice: deny file-write-data

I am working through some crash logs and keep seeing messages like this one:

Fri Jun 25 09:09:01 unknown sandboxd[427] : MyApp(422) deny file-write-data /private开发者_开发技巧/var/mobile/Media/PhotoData

Am I doing something wrong that is causing this? This one has to do with taking photos from within the app, but I have seen others in parts of my app as well.

As far as I can tell I am seeing no errors in my app and am not trying to write to the device outside my sandbox area.

Thanks for any help you can provide.

I got this message when trying to access the ALAssetsLibrary in another thread than the apps' main thread. In my case I wasn't even able to load the assets (photo albums). Putting the calls to ALAssetsLibrary into the main thread solved this issue.