Sorry, I didn't make myself clear. Not which Windows (or other OS) version, I meant: are you using (e.g.) v0.64[.1], v0.64.26, v068[.1] or v0.68.27 of the game?
As has often been noted on here, the first edition of any update (which becomes categorizable as [.1] as in paragraph above) tends to be buggy - a corrected version (which thus has a numbering higher than [.1] ...) is then issued, which solves at least some of the newly-emerging problems.
The implication in my question was thus: make sure you are working with a recent version, ending in a number above [.1]! Even corrected versions have the odd bug, but these are far rarer than in freshly-minted updates.
If it's one of those odd, stubborn bugs, I can't help, I'm afraid. Maybe someone else on here knows. Or of course ask the Developers!