devtrackers.gg
Can't give you guys too much XP/Hour now can we?! But seriously, this is being hotfixed now. Will edit this message when it's hotfixed.
Edit: This hotfix is now deployed. The vampires will take about 10 minutes to despawn completely but I'll go in game on my J-mod and kill a bunch of them for you all.
[deleted]
Happy to explain! When changing the spiders to a non-attackable spider for the update, the spider was changed to a vampire spider which seemed fitting to the area where the tree is and it didn't have an attack option on it. However the developer didn't realise that the spider actually changed into a vampire when a player goes near it which then caused a ton of vampires to show up unannounced.