Exporting assets fail

[Gorgious56]

Re https://blender.stackexchange.com/questions/275005/addonasset-browser-utilities-export-failed

I search here for an asset browser addon,and I find this.

When I want to export assets from current file to another file,it failed.
What I do:
enter image description here

After click this,it turn to here,which is my default asset folder,nothing in the list.But I do have some files there. enter image description here I click Export Assets,a new test.blend file created,but there are only a default cube in it.And the icon of test.blend is different from other blend file. enter image description here

I remember that blend change the thumbnail from logo to real object in 3.3.0,so maybe the test.blend is an old version,which may cause trouble. I don't know whether it is my mistake or it's a bug.Could anyone help to check this?Especially waiting for the author... :)