On Sweet Home 3D version 5.7 I do not find many furniture i had in 5.5.2.

[corradoventu]

I'm sure, the same import works fine on 5.5.2 and does not work in 5.7 and message says clearly '... library "...sh3f" was successfully imported...

[corradoventu]

imported libraries (also if .zip) are correctly inserted in .eteks/sweethome3d
corrado@corrado-p8-bionic:~$ ls .eteks -AR
.eteks:
sweethome3d
.eteks/sweethome3d:
furniture languages preferences.xml textures
.eteks/sweethome3d/furniture:
3DModels-Scopia-1.6.3.zip Contributions.sh3f LucaPresidente.sh3f Scopia.sh3f
.eteks/sweethome3d/languages:
.eteks/sweethome3d/textures:
corrado@corrado-p8-bionic:~$

[corradoventu]

For the problem about library import i opened a bug:
https://bugs.launchpad.net/ubuntu/+sour ... ug/1773532
if you have a launchpad account please subscribe.

[corradoventu]

Using snap version installed in Ubuntu 18.10 from Ubuntu Software library import works fine from SH3F file contained in the ZIP files but if importing from ZIP file I have the message '.. imported' but nothing is really imported.
Also Sweet Home can't open a project located on a different partition.