drag hda asset in unreal viewport，but it keeps houdini logo，didn‘t turn into terrain.
try another sphere，if i click “bake and replace all houdini assets”,it turns into sphere.
try same step on other had asset,still houdini logo,and see a sphere in other place.

can somebody tell what's wrong with me?

Hi,

Only getting the Houdini logo can mean two things:
- HAPI / Houdini Engine failed to initialize.
- Your HDA is not generating any geometry.

Since your second HDA seems to be working fine, then my guess would be that there is an issue with your terrain HDA.
It's either not outputting anything that the plugin can handle, or there is an error with its cooking.

Did you check the message log for errors?
Did you try to open the internal houdini scene to see what the issue could be? (File > Open scene in Houdini)