error caught in the console

[Boomer-1]

[19:46:57 ERROR]: [Slimefun] X: 6,453 Y: -49 Z: 20,674 (NTW_MONITOR)
[19:46:57 ERROR]: [Slimefun] has thrown 4 error messages in the last 4 Ticks, the Block has been terminated.
[19:46:57 ERROR]: [Slimefun] Check your /plugins/Slimefun/error-reports/ folder for details.
[19:46:57 ERROR]: [Slimefun]
[19:46:57 ERROR]: [Slimefun] An Exception was caught while ticking the Block Tickers Task for Slimefun vDev - 1148
java.util.ConcurrentModificationException: nulldes in config.yml.
[19:37:0at java.util.HashMap$HashIterator.nextNode(HashMap.java:1597) ~[?:?]
[19:37:0at java.util.HashMap$KeyIterator.next(HashMap.java:1620) ~[?:?]
[19:37:0at io.github.thebusybiscuit.slimefun4.implementation.tasks.TickerTask.tickChunk(TickerTask.java:140) ~[Slimefun4-Dev (4).jar:?]
java.lanat io.github.thebusybiscuit.slimefun4.implementation.tasks.TickerTask.run(TickerTask.java:110) ~[Slimefun4-Dev (4).jar:?]ke aged wine]
at org.bukkit.craftbukkit.v1_20_R3.scheduler.CraftTask.run(CraftTask.java:101) ~[paper-1.20.4.jar:git-Paper-497]
at org.bukkit.craftbukkit.v1_20_R3.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:57) ~[paper-1.20.4.jar:git-Paper-497]]
at com.destroystokyo.paper.ServerSchedulerReportingWrapper.run(ServerSchedulerReportingWrapper.java:22) ~[paper-1.20.4.jar:?]r:?]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) ~[?:?]101) ~[SlimefunAdvancements.jar:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[?:?].java:106) ~[SlimefunAdvancements.jar:?]
at java.lang.Thread.run(Thread.java:833) ~[?:?]i.AdvancementManager.register(AdvancementManager.java:64) ~[SlimefunAdvancements.jar:?]