When the user name on Windows is set to cyrillic importing APEX cloth assets will fail. I'm not sure what other systems this may also affect, but adding a cloth apb asset to a skeletal mesh will cause the error "Failed to import APEX clothing asset from selected file." The files that are known to work are attached if any testing is needed.
I worked with IT (Yilong Wang) to set this up on my machine for testing as well as you cannot access the cyrillic keyboard via the login screen on windows without remote access to your machine.
1. Make sure you've got cyrillic user name you're logged in to.
2. Open UE4
3. Import a cloth fbx skeletal mesh (example included)
4. Open the skeletal mesh after import
5. add cloth apb file to the asset (example included)
Head over to the existingAnswerHub thread and let us know what's up.