can you tell me whats wrong with this picture??

Can anyone tell me what is wrong with our tree, besides half of the lights aren't working?? All the lights did work until about 2 weeks after we put the tree up and darn if I can find the dead or missing bulb. If you ask me its easier to just pitch that sting of lights and start new next year. IF you guess whats wrong with the tree you don't win anything just a pat on the back, so go for it guess what's wrong with our tree.