The latest Fortnite update is v9.41, which release was completely unexpected. Without a downtime, the players were simply shocked for its appearance, as it made the replays incompatible.
The update notification came within a tweet from Epic Games official Fortnite Twitter. As noted, the patch is expected to fix some issues in Creative and iOS.
https://twitter.com/FortniteGame/status/1153264973516300288
The patch doesn’t include anything of a big margin, which means there shouldn’t be any concerns about the gameplay integrity.
After the first change and update on the Fortnite’s official Twitter profile, the developers have noted that the Replays are also fixed and work on v9.41.
With that being said, there’s nothing else to worry about, as everything is back to normal.