I found one issue:

I running this mod on one of my servers.
everytime someone using the worlds barrage the logs flooding with warnings "No data fixer registered for entity"
server crashes after a bit. it happens on "The World", but probably its occurs on other stands.

idk, probably its the my fault. theres full mod list:
mod list:
macaw's furniture
jojo's bizzare survival
building gadgets

log:
[18Jun2022 23:07:38.669] [Server thread/ERROR] [net.minecraft.server.MinecraftServer/]: Encountered an unexpected exception

156 | java.lang.NullPointerException: null
157 | at net.minecraft.world.storage.WorldInfo.func_76064_a(WorldInfo.java:366) ~[?:?]
158 | at net.minecraft.world.storage.WorldInfo.func_76082_a(WorldInfo.java:302) ~[?:?]
159 | at net.minecraft.world.storage.SaveHandler.func_75755_a(SaveHandler.java:49) ~[?:?]
160 | at net.minecraft.server.MinecraftServer.func_213211_a(MinecraftServer.java:540) ~[?:?]
161 | at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:804) ~[?:?]
162 | at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:637) [?:?]
163 | at java.lang.Thread.run(Thread.java:750) [?:1.8.0_322]
164 | [18Jun2022 23:07:38.673] [Server thread/ERROR] [net.minecraft.server.MinecraftServer/]: This crash report has been saved to: /server/./crash-reports/crash-2022-06-18_23.07.38-server.txt
165 | [18Jun2022 23:07:38.674] [Server thread/INFO] [net.minecraft.server.MinecraftServer/]: Stopping server
166 | [18Jun2022 23:07:38.675] [Server thread/INFO] [net.minecraft.server.MinecraftServer/]: Saving players
167 | [18Jun2022 23:07:38.731] [Server thread/INFO] [net.minecraft.network.play.ServerPlayNetHandler/]: folder9110 lost connection: Server closed
168 | [18Jun2022 23:07:38.732] [Server thread/INFO] [net.minecraft.server.dedicated.DedicatedServer/]: folder9110 left the game
169 | [18Jun2022 23:07:38.781] [Server thread/INFO] [net.minecraft.server.MinecraftServer/]: Saving worlds
170 | [18Jun2022 23:07:38.782] [Server thread/INFO] [net.minecraft.server.MinecraftServer/]: Saving chunks for level 'world'/minecraft:overworld
171 | [18Jun2022 23:07:45.048] [Server thread/INFO] [net.minecraft.world.server.ChunkManager/]: ThreadedAnvilChunkStorage (world): All chunks are saved
172 | [18Jun2022 23:07:45.069] [Server thread/ERROR] [net.minecraft.server.MinecraftServer/]: Exception stopping the server
173 | java.lang.NullPointerException: null
174 | at net.minecraft.world.storage.WorldInfo.func_76064_a(WorldInfo.java:366) ~[?:?]
175 | at net.minecraft.world.storage.WorldInfo.func_76082_a(WorldInfo.java:302) ~[?:?]
176 | at net.minecraft.world.storage.SaveHandler.func_75755_a(SaveHandler.java:49) ~[?:?]
177 | at net.minecraft.server.MinecraftServer.func_213211_a(MinecraftServer.java:540) ~[?:?]
178 | at net.minecraft.server.MinecraftServer.func_71260_j(MinecraftServer.java:568) ~[?:?]
179 | at net.minecraft.server.dedicated.DedicatedServer.func_71260_j(DedicatedServer.java:550) ~[?:?]
180 | at net.minecraft.server.MinecraftServer.run(MinecraftServer.java:676) [?:?]
181 | at java.lang.Thread.run(Thread.java:750) [?:1.8.0_322]