Program: 169718
Project: 169718
Buggy source:
@Override public void updateEntity(){
  super.updateEntity();
  if (!this.worldObj.isRemote) {
    if (this.ticks % 40 == 0) {
      PacketHandler.sendPacketToClients(this.getDescriptionPacket(),this.worldObj,new Vector3(this),35);
    }
 else     if (this.ticks % 3 == 0) {
      for (      EntityPlayer player : this.playersUsing) {
        PacketDispatcher.sendPacketToPlayer(this.getDescriptionPacket2(),(Player)player);
      }
    }
  }
  if (this.getEnergyHandler().checkExtract()) {
    this.isPowered=true;
    this.rotation+=0.08f;
    if (this.rotation > 360) {
      this.rotation=0;
    }
    if (!this.worldObj.isRemote) {
      this.getEnergyHandler().extractEnergy();
      int prevDetectedEntities=this.detectedEntities.size();
      this.doScan();
      if (prevDetectedEntities != this.detectedEntities.size()) {
        this.worldObj.notifyBlocksOfNeighborChange(this.xCoord,this.yCoord,this.zCoord,this.getBlockType().blockID);
      }
      updateClient();
      if (this.ticks % 20 == 0 && this.incomingMissiles.size() > 0) {
        for (        IBlockFrequency blockFrequency : FrequencyGrid.instance().get()) {
          if (blockFrequency instanceof TileLauncherPrefab) {
            TileLauncherPrefab launcher=(TileLauncherPrefab)blockFrequency;
            if (new Vector3(this).distance(new Vector3(launcher)) < this.alarmRange && launcher.getFrequency() == this.getFrequency()) {
              if (launcher instanceof TileLauncherScreen) {
                double height=launcher.getTarget() != null ? launcher.getTarget().y : 0;
                launcher.setTarget(new Vector3(this.incomingMissiles.get(0).posX,height,this.incomingMissiles.get(0).posZ));
              }
 else {
                launcher.setTarget(new Vector3(this.incomingMissiles.get(0)));
              }
            }
          }
        }
      }
    }
  }
 else {
    this.isPowered=false;
    if (detectedEntities.size() > 0) {
      worldObj.notifyBlocksOfNeighborChange(this.xCoord,this.yCoord,this.zCoord,this.getBlockType().blockID);
    }
    if (!this.worldObj.isRemote) {
      incomingMissiles.clear();
      detectedEntities.clear();
      detectedTiles.clear();
      updateClient();
    }
  }
  if (ticks % 40 == 0) {
    worldObj.notifyBlocksOfNeighborChange(this.xCoord,this.yCoord,this.zCoord,this.getBlockType().blockID);
  }
}

Fixed version (ground truth):
@Override public void updateEntity(){
  super.updateEntity();
  if (!this.worldObj.isRemote) {
    if (this.ticks() % 40 == 0) {
      PacketHandler.sendPacketToClients(this.getDescriptionPacket(),this.worldObj,new Vector3(this),35);
    }
 else     if (this.ticks % 3 == 0) {
      for (      EntityPlayer player : this.playersUsing) {
        PacketDispatcher.sendPacketToPlayer(this.getDescriptionPacket2(),(Player)player);
      }
    }
  }
  if (this.energy().checkExtract()) {
    this.isPowered=true;
    this.rotation+=0.08f;
    if (this.rotation > 360) {
      this.rotation=0;
    }
    if (!this.worldObj.isRemote) {
      this.energy().extractEnergy();
      int prevDetectedEntities=this.detectedEntities.size();
      this.doScan();
      if (prevDetectedEntities != this.detectedEntities.size()) {
        this.worldObj.notifyBlocksOfNeighborChange(this.xCoord,this.yCoord,this.zCoord,this.getBlockType().blockID);
      }
      updateClient();
      if (this.ticks() % 20 == 0 && this.incomingMissiles.size() > 0) {
        for (        IBlockFrequency blockFrequency : FrequencyGrid$.MODULE$) {
          if (blockFrequency instanceof TileLauncherPrefab) {
            TileLauncherPrefab launcher=(TileLauncherPrefab)blockFrequency;
            if (new Vector3(this).distance(new Vector3(launcher)) < this.alarmRange && launcher.getFrequency() == this.getFrequency()) {
              if (launcher instanceof TileLauncherScreen) {
                double height=launcher.getTarget() != null ? launcher.getTarget().y : 0;
                launcher.setTarget(new Vector3(this.incomingMissiles.get(0).posX,height,this.incomingMissiles.get(0).posZ));
              }
 else {
                launcher.setTarget(new Vector3(this.incomingMissiles.get(0)));
              }
            }
          }
        }
      }
    }
  }
 else {
    this.isPowered=false;
    if (detectedEntities.size() > 0) {
      worldObj.notifyBlocksOfNeighborChange(this.xCoord,this.yCoord,this.zCoord,this.getBlockType());
    }
    if (!this.worldObj.isRemote) {
      incomingMissiles.clear();
      detectedEntities.clear();
      detectedTiles.clear();
      updateClient();
    }
  }
  if (ticks() % 40 == 0) {
    worldObj.notifyBlocksOfNeighborChange(this.xCoord,this.yCoord,this.zCoord,this.getBlockType().blockID);
  }
}