Every time I paste even just one frame from one document to another, Photoshop either crashes or becomes unresponsive.
OS: macOS 10.13.1 (17B48)
PS CC 2018: 19.0 Release
It happens when I am pasting even 1 frame of a solid color no matter the canvas size (video below shows a 100x100px canvas).
Photoshop has been removed (and the preferences) and reinstalled and the issue persists. Very annoying.
Could you please try updating Photoshop to version 19.0.1 which is the recently released version.
You can update it via the Creative Cloud application, click on the fly-out on the top right corner then choose "Check for Updates".
Please let us know if it helps.