Sorry I didn't catch this before 8.0.3's release, but I discovered today after updating to it that text in standard text fields (i.e. fields not designated for variables or calculations) is not editable (including cut, copy, and paste actions, though that may go without saying). Hopefully this image will be enough to demonstrate the issue:
I'm unsure if this existed in versions prior to 8.0.3 as well, but it certainly exists for me now (at least in High Sierra 10.13.0, which I'm now running).