Issue

• I've downloaded any character from Mixamo
• Those files normally 1MB and in a few seconds you can import them
• Trying to import to the project
• First, I see a progress bar, then basically no action on the editor, freezes
• Waited minutes
• I can only close the editor from the task-manager
• I'm using the Unreal Editor 5.3.1 version

This wasn't always the case, it started randomly. I can't go further.

Solution

Here is how I was able to solve it:

While importing the FBX file:

• It will open the file explorer at the beginning
• And in that window, at the bottom right, there is a dropdown list, it is set to all files by default which didn’t work → Sometimes freezes → Sometimes not
• Choose “FBX Skeletal Meshes (*.fbx)” from the dropdown list of file types
• If you import it like that, it imports very well

I hope it will help someone.