Cannot Dust Hysteria

Running latest Hearthstone under macOS 10.13.6. I recently opened a pack and gained a 3rd Hysteria card. The system will not allow me to dust it. I can select it, click on Disenchant, and it goes through the motions, but when I click in the background to dismiss the Dust/Build module, a small window comes up titled “Collection Error!” that reads “Something went wrong. try again.” (The capitalization error is not mine.) I have tried repeatedly, under both classes, and have quit and re-run the game client with no change.