startup errors in 1.15.2

[mrcoffee1026]

Description (Required)

Errors flood to log from startup.

Steps to reproduce the Issue (Required)

Start server in 1.15.2 with active barrels in the world.

Expected behavior (Required)

To startup without these errors.

Server Log / Error Report

https://pastebin.com/0AgEXaYR

Environment (Required)

[21:59:04 INFO]: Paper v1_15_R1 (67)
[21:59:04 INFO]:
[21:59:04 INFO]: CS-CoreLib vDEV - 80 (git e3242c60)
[21:59:04 INFO]: Slimefun vDEV - 408 (git 73b64e87)
[21:59:04 INFO]:
[21:59:04 INFO]: Installed Addons (13)
[21:59:04 INFO]: Barrels vDEV - 8 (git 447cb)
[21:59:04 INFO]: DyedBackpacks vDEV - 1 (git 4b4d1f0f)
[21:59:04 INFO]: ElectricSpawners vDEV - 6 (git 845b6076)
[21:59:04 INFO]: SlimefunOreChunks vDEV - 3 (git 7ddf966e)
[21:59:04 INFO]: SlimeXpansion vDEV - 4 (git 5bf10c29)
[21:59:04 INFO]: ExtraHeads vDEV - 9 (git 32435a1f)
[21:59:04 INFO]: SoulJars vDEV - 10 (git 58202ab6)
[21:59:04 INFO]: HotbarPets vDEV - 23 (git 37b50104)
[21:59:04 INFO]: SlimyTreeTaps vDEV - 3 (git c4f773fa)
[21:59:04 INFO]: PrivateStorage vDEV - 8 (git 6b242fc5)
[21:59:04 INFO]: ExtraGear vDEV - 3 (git de222ab7)
[21:59:04 INFO]: ChestTerminal vDEV - 20 (git a698c614)
[21:59:04 INFO]: ExoticGarden vDEV - 25 (git b5fce971)

[mrcoffee1026]

this sseems to have resolved itself with later sf builds.