invalid context 0x0 under iOS 7.0 and system degradation

If you're curious what code is causing these logs, you can add a symbolic breakpoint on CGPostError.

Others will ask you to post the code where you access a core graphics context, but I doubt that's the issue. These invalid context 0x0 error messages are common and easy to reproduce in iOS 7. In fact, I can reproduce the error using storyboard with zero code. I drag a UITextField onto the canvas in IB, run the app, and double tap inside the text field.

In many situations, it's hard for me to take the invalid context 0x0 error messages seriously. I don't know if your situation warrants greater concern (I agree with Rob Napier that it's worth investigating, especially if you are explicitly using a graphics context).

In my own projects, I'm hoping that many of these errors magically disappear some day (but that day did not come with 7.0.3).

Update: After installing Xcode 5.1 and targeting iOS 7.1, I can no longer reproduce the error by double tapping inside an empty text field.

UIGraphicsBeginImageContext( size );
CGContextRef context = UIGraphicsGetCurrentContext();

make sure the size.width or size.height is not 0,

you can add symbol breakpoint to CGPostError to check

These sorts of errors are historically the result of calling Core Graphics functions when not within a context that is established within drawRect or between calls like UIGraphicsBeginImageContext and UIGraphicsEndImageContext (or other UIKit functions like that which begin and end a context).

Having said that, though, bilobatum is correct that this particular sequence of errors can be a result of that iOS 7 bug he references in his answer. If not seeing these errors in your iOS6 targets, or if after a quick scan of this private framework you don't find any suspect Core Graphics calls, it may just be this iOS 7 bug. Good catch, bilobatum!