Hi. We're evaluating Houdini for Unreal and everything went well until now. Whenever I reimport and recook an HDA I get this error:

"Cook Results:
HAPI Error: The node is invalid. Either the otl/hda asset library file was deleted or another otl/hda asset library file was loaded that contained an operator type with the same name as this asset's operator type. You must unload this node's asset and re-instantiate it.

Cook State:
Ready with Fatal Errors - Evaluating python"

If I delete the instance in the scene and make a new instance it works like it should. Any ideas appreciated.


Windows, Houdini 18.5.696, Unreal 4.27 and latest houdini engine for 18.5.696/4.27.

Or, mostly I get:

"Cook Results:
Invalid argument given: Invalid id.

Cook State:
Ready with Fatal Errors"



When I create an instance of an HDA in a scene, everything works until I reimport and recook, without fail. I'm a bit stuck just trying to get past this, it's almost impossible get any work done.



This is V2. Happens in my main scene, but I tried it in a new scene, same thing.

One more update: If I press "recook" and "rebuild" repeatedly in the details panel it eventually works and recooks...

i've run into similar issues and i don't know what's at fault. and yeah i've had to do similar stuff like you where i rebake or reload the map or unreal to try and get around it. not fun.