Oh dear, it seems that the lights on your pre-lit Christmas tree have malfunctioned. Don't worry, I can help you troubleshoot the issue. Here are some steps you can follow to try and fix the lights:
1. Check the fuse: Check the fuse on your pre-lit Christmas tree to make sure it hasn't blown. You can find the fuse on the plug or on a panel in the base of the tree. If the fuse has blown, you will need to replace it.
2. Check the light bulbs: Take a look at the light bulbs to make sure they are in place and not loose.