Marvelous Designer Support

Hi all,

I'm a complete newbie here, so I apologize if this is a very basic question. 

I am trying to use Marvelous Designer to design clothing for Daz. I can successfully import avatars from Daz, but as soon as I do *anything* in MD the avatar simply disappears. Create a simple polygon? Boom, avatar disappears from the screen and all windows. Load a piece of clothing? POOF! It's replaced by whatever else I just created and seems to completely disappear. Ctrl-Z does not bring it back.

What am I doing wrong? I'm certain it's something absolutely stupid and simple that I'm missing, but like I said, I'm totally new to MD. 

To try to debug this I've:

- Read approximately five million tutorials

- Googled everything I could think of for days

- Watched what feels like a dozen YouTube videos
- Purchased a Udemy course on MD in general. MD works fine right up until I try to import an OBJ file avatar, and I've been successfully designing clothing on MD avatars. I just can't import an avatar from Daz.
Attempted to import various different types of Daz figures. (Everything from Genesis 3 to Genesis 9 -- same result.)
- Rebooted my computer quite a few times.
- Reinstalled MD
- Cussed a bit

My system should be able to easily support whatever it needs to do. (Newer gaming PC that has zero issues with anything Daz or Blender throws at it -- can dig up the exact specs if anyone thinks this might be a hardware issue.) I don't think it's a hardware issue.  

Help? What am I missing? 

Edit to add: Just tried to import an avatar an FBX file. It seems to work okay as an FBX, but OBJ files still go poof.