Selecting nodes and pressing Command-C then Command-V (either in the same shader, or between two different shaders) does nothing in Shader Forge. It does flash the "Edit" menu in the menu bar, which is the same behaviour when copying/pasting an object in the scene editor (though thankfully objects selected in the scene are not erroneously copied or pasted while using ShaderForge!).
Command-D duplicates as expected; it just doesn't help with transferring large node networks from one shader to another. This would seem to indicate that there's something wrong with copy/paste specifically, not necessarily the keyboard system (though I'm very likely wrong :D).
Control-C and Control-V simply bring up the node menu as if Control wasn't pressed at all. Control-D does not duplicate (tested just in case Windows style shortcuts were working when Mac shortcuts weren't).
Tested on a MacPro running OSX 10.11.6, Unity 5.6.3P2 (though I had the same issues in other versions of Unity too), and ShaderForge 1.38 (curiously, I don't think I've ever been able to copy/paste, it just happens to be especially necessary today and I can't!).
While I do typically have BetterTouchTool and Alfred running (both of which allow for customisation of keyboard behaviour, and are therefore a possible source of conflicts), I've tested without either of these utilities running and the results were exactly the same (copy/paste never worked). I disabled assistive devices in System Preferences as well (the method by which many OSX utilities modify keyboard events), and that didn't help either.
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