'Export As' Broken

I've restarted and retried, but I cannot use "Export As" anymore after updating this morning. It just freezes on a blank screen.

macOS Mojave

Version 10.14.6

iMac (Retina 5k, 27-inch, Late 2014)

Memory 32 GB 1600 MHz DDR3

Graphics AMD Radeon R9 M290X 2 GB