Issue: Using mouse, storyboard objects such as labels and buttons are not responding to drag and resize.
Solution: Use the size inspector to input and adjust size and location of the object instead:
Open Xcode, go to the Main Storyboard
Select the object you wish to adjust
A menu on the right side of the screen will appear. Please click on the ruler icon called "Show the Size Inspector" (It is the 5th icon from the left)
- This will open a new menu providing you options to adjust the X/Y coordinates of the object, its Width/Height, and several other layout options
See the following screenshot which shows the location of the view size adjustment fields: