@fongmo: I can't reproduce the issue with latest game version. It's possible that you have light version installed (can be selected in the launcher), where only header part of some assets is present, while bulk data is downloaded at runtime while you're playing. Trying to open such incomplete assets will lead to issues similar to the one from your error.
I truly didn’t realize where the problem stemmed from at all. I had installed the lightweight version previously, and after switching to the standard edition just now, the problem no longer occurs, with all model assets loading smoothly.
Incidentally, an error appeared when I accidentally clicked a map asset, which I assume is normal.
I’m extremely thankful for your kind assistance! This issue has been bothering me for quite some time, and I really appreciate you taking your valuable time to reply to my message.