Observed on the 17/4/21 via analytics for 1.16.5-2.1:

Stacktrace:
java.lang.NullPointerException at bassebombecraft.entity.EntityUtils.setAttribute(EntityUtils.java:457) at bassebombecraft.operator.entity.raytraceresult.SpawnDecoy2.run(SpawnDecoy2.java:141) at bassebombecraft.operator.Operators2.run(Operators2.java:20) at bassebombecraft.operator.Operators2.run(Operators2.java:39) at bassebombecraft.operator.Sequence2.run(Sequence2.java:71) at bassebombecraft.operator.Operators2.run(Operators2.java:20) at bassebombecraft.event.projectile.ProjectileModifierEventHandler.spawnDecoy(ProjectileModifierEventHandler.java:447) at bassebombecraft.event.projectile.ProjectileModifierEventHandler.handleProjectileImpactEvent(ProjectileModifierEventHandler.java:270) at net.minecraftforge.eventbus.ASMEventHandler_118_ProjectileModifierEventHandler_handleProjectileImpactEvent_ProjectileImpactEvent.invoke(.dynamic) at net.minecraftforge.eventbus.ASMEventHandler.invoke(ASMEventHandler.java:85) at net.minecraftforge.eventbus.EventBus$$Lambda$2535/2095763316.invoke(Unknown Source) at net.minecraftforge.eventbus.EventBus.post(EventBus.java:302) at net.minecraftforge.eventbus.EventBus.post(EventBus.java:283) at net.minecraftforge.event.ForgeEventFactory.onProjectileImpact(ForgeEventFactory.java:633) at bassebombecraft.entity.projectile.GenericCompositeProjectileEntity.handleImpact(GenericCompositeProjectileEntity.java:339) at bassebombecraft.entity.projectile.GenericCompositeProjectileEntity.func_70071_h_(GenericCompositeProjectileEntity.java:306) at net.minecraft.world.server.ServerWorld.func_217479_a(ServerWorld.java:611) at net.minecraft.world.server.ServerWorld$$Lambda$11671/1362405145.accept(Unknown Source) at net.minecraft.world.World.func_217390_a(World.java:554) at net.minecraft.world.server.ServerWorld.func_72835_b(ServerWorld.java:404) at net.minecraft.server.MinecraftServer.func_71190_q(MinecraftServer.java:851) at net.minecraft.server.MinecraftServer.func_71217_p(MinecraftServer.java:787) at net.minecraft.server.integrated.IntegratedServer.func_71217_p(IntegratedServer.java:78) at net.minecraft.server.MinecraftServer.func_240802_v_(MinecraftServer.java:642) at net.minecraft.server.MinecraftServer.func_240783_a_(MinecraftServer.java:232) at net.minecraft.server.MinecraftServer$$Lambda$11210/1925284156.run(Unknown Source) at java.lang.Thread.run(Unknown Source) chok328;Windows 8.1,6.3,amd64;1.8.0_51;JVM args:-Djava.net.preferIPv4Stack=true;-Xmn128M;-Xmx4072M;-XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump;-Xss1M;-Djava.library.path=C:\Users\XXX\AppData\Roaming\.minecraft\versions\Forge 1.16.5\natives;-Dminecraft.launcher.brand=minecraft-launcher;-Dminecraft.launcher.version=2.0.1003;-Dminecraft.applet.TargetDirectory=C:\Users\XXX\AppData\Roaming\.minecraft;-XX:+UnlockExperimentalVMOptions;-XX:+UseG1GC;-XX:G1NewSizePercent=20;-XX:G1ReservePercent=20;-XX:MaxGCPauseMillis=50;-XX:G1HeapRegionSize=32M;-Dfml.ignoreInvalidMinecraftCertificates=true;-Dfml.ignorePatchDiscrepancies=true;1.16.5;36.1.4;20210115.111550;

See analysis of spawn decoy attribute error in #1182.

Resolved with commit: 4b8111d