If you run into difficulties, for no apparent reason, while attempting to restore a drive from an image using Disk Utility, you may be able to get around this by using this method of selecting the source and destination.
I can’t say why this works, but normally I would simply drag-and-drop my source and destination into their respective fields. However, if the imaging fails you can try selecting each by right-clicking on that item (in the left pane) and choosing either “Set as source” or “Set as destination” from the menu which appears.
(If you do not enable right-click, ctrl-click will produce the same menu.)
So far this has worked in every instance where the image should function but was not working using the other methods of selecting the source and destination. As they say, your mileage may vary.
Go get ’em.