wb fill, skipping unknown entity in 1.15.1

[mrfloris]

>cmi tps
[19:37:16] [Server thread/INFO]: TPS: 15.06 (9.17 10.12 10.80 13.26)
[19:37:18] [Server thread/INFO]: [WorldBorder] [Fill] 217 more chunks processed (328898 total, ~82.7%) (free mem: 2489 MB)
>tps
[19:37:21] [Server thread/INFO]: TPS from last 1m, 5m, 15m: 11.77, 14.87, 16.09
[19:37:23] [Server thread/INFO]: [WorldBorder] [Fill] 360 more chunks processed (329258 total, ~82.8%) (free mem: 3184 MB)
[19:37:28] [Server thread/INFO]: [WorldBorder] [Fill] 384 more chunks processed (329642 total, ~82.9%) (free mem: 6642 MB)
[19:37:29] [Server thread/WARN]: Skipping Entity with id
[19:37:33] [Server thread/INFO]: [WorldBorder] [Fill] 367 more chunks processed (330009 total, ~83.0%) (free mem: 3406 MB)
[19:37:33] [Server thread/INFO]: [WorldBorder] [Fill] Saving the world to disk, just to be on the safe side. (free mem: 3406 MB)

>ver WorldBorder
[19:38:42] [Server thread/INFO]: WorldBorder version 1.9.10 (beta)
[19:38:42] [Server thread/INFO]: Efficient, feature-rich plugin for limiting the size of your worlds.
[19:38:42] [Server thread/INFO]: Author: Brettflan
>ver
[19:38:43] [Server thread/INFO]: This server is running CraftBukkit version git-Spigot-492a779-731e819 (MC: 1.15.1) (Implementing API version 1.15.1-R0.1-SNAPSHOT)
[19:38:43] [Server thread/INFO]: You are 1 version(s) behind
>

Would it be possible to have it auto stop when it hits TPS 18 for example? Before once it gets below 10 for a few minutes it crashes.

Anyway, i noticed every blue moon on freshly created 1.15.1 worlds with spigot 1.15.1 that it once in aw hile skips an unknown entity, there's no id. I do not think it's a major issue or a problem, but i wouldn't mind knowing what type of entity it has an issue with or how i can fix that.

Looking forward to a release with better 1.15.1 support and some more options to give us a bit more control