I have a sim couple. She's an artist and he's in the astronaut career. The last time he went to work, when it was time for him to return home, I could hear him outside the house but couldn't see him. Also, his portrait said he was still at work. I tried to click on him and have him come home early, hoping that would fix it. But it didn't. I then went into manage worlds, went into build mode on another lot, came out and clicked on my household to play it again. Now his portrait still said he was at work but he was showing at home and was eating. I could click on him and queue things for him to do but I couldn't see his needs, or anything like that as the game still thought he was at work. So I tried resetting him. That didn't work.
Here's what fixed it. I had him travel, along with his fiance, to the gym and when they got there, he was fixed AND his promotion to level 4 Astronaut appeared.
Thought I'd share the fix in case it happened to anyone else.