Thank you for your reply. I eventually stopped trying to fix the localisation file and instead deleted the mod and recreated it in the launcher. That fixed the issue. So my gut feeling was probably wrong and it was instead some problem in the mod id file instead, not in the localisation. It was just a coincidence that the issue occurred after I changed the location file.You localisation strings seem correct though, as compared to those in apocalypse_l_english and l_english files.
Did you try to comment out HUMAN4 and check if HUMAN5 is clear?
And unrelated follow-up: what's up with the steam workshop and the thumbnails? What would be so hard about letting us upload a thumbnail directly unto steam?