Sometimes this error pops up when running an app on an iOS device:

• Could not change executable permissions on the application.

Usually this is caused by an app with a re-purposed Bundle Identifier. If you create a new app and use the same Bundle Identifier as a different app that is already installed, then Xcode can get confused and thinks it should still be the same app (which it no longer is).

Find which app it is, delete it from the device and run it again from Xcode. This *should* solve your problem.