The error message can show up in the debugger during the initialization stage:
Failed to create engine. Invalid license. Make sure you have a valid license file and specify correct 'bundle id'
Sample projects in MobileCapture SDK and RealTime Recognition SDK are looking for a path that is defined in a licensePath variable. For example, our iOS samples are looking for a file called "license" (without any file extensions) in the "assets" folder.
Make sure that your code is referring to the correct license file.