Yikes! This must have slipped by our testing somehow. I've rolled back to 1.8.35, which is now the latest. Unfortunately it is super late here right now so I'll fix it first thing in the morning and release 1.8.37. Sorry!
If you accidentally saved after this happened, please look in your Spine backup folder. Spine saves a copy of the project to the backup folder before every save. You can find the backup folder by clicking the Spine logo in the upper left, the Settings, then "backup".