I have been getting this error the whole day now, cause by this specific mod.
This is the command line output before crash.

LOG : General , 1727741113305> 5,349,360> Workshop: item state CheckItemState -> Ready ID=2577049038
LOG : General , 1727741113312> 5,349,365> Workshop: GetItemState()=Installed ID=1510950729
LOG : General , 1727741113322> 5,349,376> Workshop: item state CheckItemState -> Ready ID=1510950729
LOG : General , 1727741113330> 5,349,384> Workshop: GetItemState()=NeedsUpdate ID=2335368829
LOG : General , 1727741113334> 5,349,388> Workshop: item state CheckItemState -> DownloadPending ID=2335368829
LOG : General , 1727741113375> 5,349,429> Workshop: DownloadPending GetItemState()=NeedsUpdate|DownloadPending ID=2335368829
LOG : General , 1727741113395> 5,349,449> Workshop: download 0/182550624 ID=2335368829
LOG : General , 1727741113496> 5,349,550> Workshop: DownloadPending GetItemState()=NeedsUpdate|DownloadPending ID=2335368829
LOG : General , 1727741113498> 5,349,552> Workshop: download 0/182550624 ID=2335368829
LOG : General , 1727741113601> 5,349,655> Workshop: DownloadPending GetItemState()=NeedsUpdate|DownloadPending ID=2335368829
LOG : General , 1727741113602> 5,349,656> Workshop: download 0/182550624 ID=2335368829
LOG : General , 1727741113708> 5,349,761> Workshop: DownloadPending GetItemState()=NeedsUpdate|DownloadPending ID=2335368829
LOG : General , 1727741113711> 5,349,765> Workshop: download 0/182550624 ID=2335368829
LOG : General , 1727741113811> 5,349,865> Workshop: DownloadPending GetItemState()=NeedsUpdate|DownloadPending ID=2335368829
LOG : General , 1727741113812> 5,349,866> Workshop: download 0/182550624 ID=2335368829
LOG : General , 1727741113915> 5,349,969> Workshop: DownloadPending GetItemState()=NeedsUpdate|DownloadPending ID=2335368829
LOG : General , 1727741113916> 5,349,970> Workshop: download 0/182550624 ID=2335368829
LOG : General , 1727741114427> 5,350,481> Workshop: DownloadPending GetItemState()=NeedsUpdate|DownloadPending ID=2335368829
LOG : General , 1727741114441> 5,350,495> Workshop: download 0/182550624 ID=2335368829
LOG : General , 1727741114475> 5,350,529> Workshop: DownloadPending GetItemState()=NeedsUpdate|Downloading|DownloadPending ID=2335368829
LOG : General , 1727741114476> 5,350,530> Workshop: download 0/182550624 ID=2335368829
LOG : General , 1727741114577> 5,350,632> Workshop: DownloadPending GetItemState()=NeedsUpdate|Downloading|DownloadPending ID=2335368829
LOG : General , 1727741114579> 5,350,633> Workshop: download 0/182550624 ID=2335368829
LOG : General , 1727741114687> 5,350,741> Workshop: DownloadPending GetItemState()=NeedsUpdate|Downloading|DownloadPending ID=2335368829
LOG : General , 1727741114688> 5,350,742> Workshop: download 0/182550624 ID=2335368829
LOG : General , 1727741114805> 5,350,859> Workshop: DownloadPending GetItemState()=NeedsUpdate|Downloading|DownloadPending ID=2335368829
LOG : General , 1727741114806> 5,350,860> Workshop: download 0/182550624 ID=2335368829
LOG : General , 1727741114965> 5,351,019> Workshop: onItemNotDownloaded itemID=2335368829 result=2
LOG : General , 1727741114965> 5,351,019> Workshop: item state DownloadPending -> Fail ID=2335368829
#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x00007f351674cd46, pid=17634, tid=17748
#
# JRE version: OpenJDK Runtime Environment Zulu17.30+15-CA (17.0.1+12) (build 17.0.1+12-LTS)
# Java VM: OpenJDK 64-Bit Server VM Zulu17.30+15-CA (17.0.1+12-LTS, mixed mode, sharing, tiered, compressed class ptrs, z gc, linux-amd64)
# Problematic frame:
# C [libpthread.so.0+0xdd46] pthread_rwlock_wrlock+0x16
#
# Core dump will be written. Default location: Core dumps may be processed with "/lib/systemd/systemd-coredump %P %u %g %s %t 9223372036854775808 %h" (or dumping to /home/pzuser/pzserver/core.17634)
#
# An error report file with more information is saved as:
# /home/pzuser/pzserver/hs_err_pid17634.log
#
# If you would like to submit a bug report, please visit:
# http://www.azul.com/support/
#
./start-server.sh: line 26: 17634 Aborted (core dumped) LD_PRELOAD="${LD_PRELOAD}:${JSIG}" ./ProjectZomboid64 "$@"
pzuser@billy-server:~/pzserver$

Something causes Java Runtime to shiz it's pants and crash on download.