I have this same problem. I have a .PSD with 4 layers (each one a smart object). No matter what instructions I give the layer name for image asset generation (64 x 64 picture.jpg or 64 x 64 image.png) it only generates files with size of 0kb and nothing on them. When I try to open one of the generated files, Photoshop opens the new file dialog box.
I tried opening an older .PSD with dozens of smart object layers that used to work and it's broken now too. It generates dozens of .PNG files that are 0 kb in size with nothing in them.
EDIT: I'm using Windows 10 with the latest version of Photoshop (2017.1.1). Really hating the cloud updates. I wish I could keep a stable version I'm familiar without downloading new buggier versions every 6 months. I guess it's my fault for updating.
Just out of interest what machine do you have?
Does quick export to png work?
If you do export, export as does anything appear in the pop-up window?
Dell XPS 15. I did the Quick Export and I didn't get a pop-up window or anything. I never found the .png file if it made one.
What did work for me (restored the Generate > Image Assets functionality) was to uninstall Photoshop via the Windows "Add/Remove Programs" option. Completely removed my preferences too (annoying but probably what fixed it). I then reinstalled Photoshop from the Creative Cloud application and it's working normally.
Interesting I also have a Dell XPS 15.
Try opening your support assist. Can you see it?
If you can't try opening the NVIDIA control panel and setting the app to run from the NVIDIA card instead of the Intel one. This one was of the weird symptoms I had as well.
I think it might have something to do with the intel videodriver 126.96.36.19990 as that's when I started having the issues.
It seems to be OK for me now. If you think it might be the same problem go to the dell support site and update your NVIDIA and intel graphics cards
Hope this helps