mesh converter: generated prefab asset is missing mesh data

[unitycoder]

details, https://forum.unity.com/threads/released-point-cloud-viewer-tools.240536/page-16#post-8468564

current workarounds:

• convert without adding the the "add to scene", then manually copy the mesh files, then do the same process again and manually drag/link the mesh files from previous step

[unitycoder]

fixed in the next update (v2.80)