Hmm Crazy Ivan made update for SCX IIc with corrections for version 1.08
This patch includes improved navalsimengine.dll and subcommand.exe in version 1.08
You should try it.
Link
(update attached to first post)
edit:
I did a fresh SC installation (I have SC from a naval pack non-steam box) + SCXIIc + upgrade, but game doesn't start