I do have a very strange problem since iOS 10.1.1. In my App I've configured a proxy for the NSURLSessionConfiguration object so the App can use the proxy and there does not need to be a proxy configured in the WLAN settings of the system.
The proxy requires authentication. So the App will eventually ask for user name and password when the delegate method "URLSession:task:didReceiveChallenge:completionHandler:" and makes sure that the request can continue.
This worked fine before and still does under iOS 10.1.1, but since updating to iOS 10.1.1 the iOS itself opens an alert view stating the a proxy authentication is required and gives the user the choice to do this "later" or directly go to the system settings. This alert box is completely silly, because the system settings do not have any proxy configured for which the user can enter any credentials. Also this alert view is shown by the iOS even before(!!) the above "didReceiveChallenge" delegate method of NSURLSession is called. So its impossible to avoid this silly system alert, because the App does not get a chance to provide the credentials before the iOS displays this alert.
Does anyone else seeing this and knows how to fix this?
BTW: When this iOS alert appears, I do get the following in the console of XCode:
*** WARNING: CFMachPortSetInvalidationCallBack() called on a CFMachPort with a Mach port (0x2a07) which does not have any send rights. This is not going to work. Callback function: 0x18e5967d8
This all seems to be new since iOS 10.1.1