Couple of questions:
- Does this happen only with Skeletal Mesh FBXs or simple mesh FBXs as well?
- Which version of FBX are you exporting (2014/2015, 2016 version), assuming you’re using Max/Maya and can choose during the export process?
- Can you provide a simple test asset and source file that causes this?
- Can you try to import the FBX and then close and save the project. Knowing this will give the error, I need you to go to the project folder and grab the log (project folder > saved > Logs) and post that here as an attached text file. Maybe this will have something that is useful in it.
Thank you!
Tim