Export to 3ds does not retain welded vertices

I found solution about this into the Autodesk 3ds Max Services & Support. Interesting is that this problem applies to all 3ds Max versions (!).

Issue: When you export to 3ds, the geometry is exported but some vertices are not welded together.

Solution: To export welded vertices to 3ds:

1. Select the geometry
2. Right-click it and select Convert To Editable Poly
3. Press “1” to go under the vertex selection mode
4. Press Ctrl-A to select all vertices
5. In the Parameters > Edit Vertices rollout, click Weld to weld all vertices. Leave the weld value to its default.