level 4 of woodworking is still locked though I am already on level 5

I am currently trying to finish the quest where you have to craft a weird ornament in another sims town. The game has been crashing a lot when one of my sims is at another sims town. Once when I finally crafted a weird ornament and was about to do the next quest (kick over a trash can), the game crashed and I was forced to reopen it. When I did, the weird ornament was gone and I was back where I was before I crafted the thing. However, I later found that when I reached level 5 in woodworking, level 4 was still locked..... What am I supposed to do? I've tried sending another sim there (who is level 1), but he crafted a level 5 object.... WHAT SHOULD I DO????