Warhammer 40,000: Darktide is the latest co-op horde shooter from Fatshark, the developer best known for their work on Warhammer: Vermintide and its sequel. Small updates have been rolling out for Darktide consistently since its launch, as Fatshark strives to improve the performance of the game.
The latest hotfix which updates the game to version 1.0.21, does come with some improvements in the form of adding AMD ray-tracing support and the ability to detect high-performance GPUs in laptops. However, Darktide's most recent hotfix has also removed the ability to see player outlines.
This feature could be seen as quite vital for co-op play, as it can help track teammates when they aren't immediately in your line of sight. Fatshark has assured players it isn't permanently removing the feature, though, and that the outlines are currently not working as intended according to the patch notes on Steam.
The player outlines will return in the near future, though Fatshark hasn't exactly confirmed when that will be. Hopefully, the outlines can return and work as intended sooner rather than later.