I am seeing this when changing an Input Path (curve) to one of my HDAs. Nothing has changed in terms of version of H16 or UE4 between now and when it worked. I've attempted to Re-import the HDA and to “Rebuild All Instances” but the issue remains.

Can someone advise please?

EDIT: When I use “Recook Asset” it's fine, so it's just when changing the Input Path there is an issue.

If you attach your HDA here or to a bug report we'll be able to take a look.

OK, please see attached HDA file and screenshot of UE4 showing curve settings etc.

I am using UE4.16.1 and H16.0.638 (Indie)