It's a relatively harmless (I believe) bug in the iOS 7 SDK.
https://devforums.apple.com/message/940094#940094
I had the same issue and found your post when searching for a solution. My application appeared to be running fine but I was still getting this message I was able to eliminate the message on my machine, here is what I had to do;
Stop all execution on the simulator. Go to the simulator's home screen using shift-command-h. Delete the app from the simulator device by holding a click on my program until the delete icon appeared, then click the X to delete. In the iOS Simulator select Reset Content and Settings. Clean the project in Xcode, shift-command-k. Build it and run it.
Note, I was doing steps 4 & 5 but that wasn't working. It wasn't until I added step 3 (as crazy as it sounds) that it cleared my message.
Hope this works for you!
--Dave
Perhaps deleting the app, resetting, and restarting the iOS simulator would work.