Get Attack Target

The issue I've had is that I have created a wizard using the witch AI base that chases players, villagers and golems and attacks them with potions and special abilties like spawning Evoker fangs and vexes on the target entity.

The problem I've been having is after the target is dead the game crashes.

I'm using MCreator 2020.4

Here is the code that is crashing (I didn't make it it's the MCreator generated code)

if (world instanceof World && !world.getWorld().isRemote) {
                        Entity entityToSpawn = new EvokerFangsEntity(EntityType.EVOKER_FANGS, world.getWorld());
                        entityToSpawn.setLocationAndAngles(
                                (((-2) + (4 * Math.random()))
                                        + (((entity instanceof MobEntity) ? ((MobEntity) entity).getAttackTarget() : null).getPosX())),        <--------- This line was where it said was crashing
                                y,
                                (((-2) + (4 * Math.random()))
                                        + (((entity instanceof MobEntity) ? ((MobEntity) entity).getAttackTarget() : null).getPosZ())),
                                world.getRandom().nextFloat() * 360F, 0);
                        if (entityToSpawn instanceof MobEntity)
                            ((MobEntity) entityToSpawn).onInitialSpawn(world, world.getDifficultyForLocation(new BlockPos(entityToSpawn)),
                                    SpawnReason.MOB_SUMMONED, (ILivingEntityData) null, (CompoundNBT) null);
                        world.addEntity(entityToSpawn);
                    }

I was wondering if there was a way to check if there is a target entity before spawning something on it as I believe that is why it is returning a crash