using factorio 0.17.45, version 1.0.0 is downloaded when using the ingame mod manager,
and i get the same error (real expected, got nil) ...
i saw similar problems with the ingame mod portal with other mods too, and all of them seem to have in common that the versions are ordered "backwards". this also causes the "version" and "last updated" columns to be shown as "---" only. thus it seems to be a bug in factorio ...
as a temporary fix, the most current version can be downloaded directly from the mod portal website after deleting the old version (either in the mod directory or by deleting it in the ingame mod manager). but any attempt to download it ingame will end with the wrong version.