latest LR CC classic Version.
a few times now i had Images imported twice,
the files are in the LR catalog already but when i use "synchronize folder" they are imported again, a second time.
so for example, i end up with 160 files in a folder that only contains 80 files.
it happens not always and not to the same folder.
i have no clue why this happens but it ́s an issue i only have with the new LR CC classic.
this is on a fresh win10 1709 Installation with a fresh LR CC classic installation and a new created catalog.
more infos here: