OK so I was travelling back from the future with a family of four, on the way back it took a lot longer than expected. When I got back one of my sims (a ghost called bob mclain) was just gone. In the relationships tab they were greyed out but my sims could still call him, the picture didn't show the 'in the future' icon. In edit town, when I viewed the house, my sim wasn't there. I then tried travel back to the future to see if he was still there the loading screen just kinda stayed stuck so i left it for half an hour then force quitted it. I reloaded the game from the future file and tried taking them back, the exact same thing happened again. I've posted a script error file that came up.
(not sure if its also related but another sim came back but off screen and stuck??? but their icon was still there so I could still reset them.)

(blows whistle loudly) Infraction! Stop right there! You are attempting to conduct world travel without the Traveler mod in play and that will not be tolerated here!

Okay, let me put that another, perhaps gentler way. Hi there, and welcome to NRaas. We have a mod called Traveler that is designed to rewrite the travel transitions specifically so that things like this don't happen. Our developer should look at the Deref section of that log and comment, but I expect that the first thing he will want to know is what happens if you try that again with the mod in place.

Hi, thanks for the response. I got the traveler mod, I travelled home and everything was exactly the same as before. The good news is that I have 3 whole new Script Errors, that I've uploaded.

Looks messy. If I had guess his outfit is causing the drama. Does he appear to function fine in the future? Try using DebugEnabler's Fix Invisible Sims while in the future then traveling back.

in the future all of my sims at least seemed to be functioning normally. I used the DebugEnabler's Fix Invisible Sims, it did seem to think that the sim needed fixing, however travelling back to the homeworld still deleted the sim (also he isn't showing in the relationship panel anymore either). I've uploaded more script errors.

Same error I'm afraid. I suspected I was right about the outfit being the problem however it appears DebugEnabler isn't saving you. As a last ditch effort, run that command then drag him into CAS and change his everyday outfit to something else then try to travel back. If it still fails I'm afraid the EA travel system without the presence of Traveler has claimed another victim.

ok so it didn't work but i managed to kinda get my sim back by uninstalling traveler and then travelling home, this meant that I could still phone the sim. I just called and invited him to come 'visit', when he got there I used cheats to re-add him to my active family. It seems to have worked as he's the same except for his inventory and the fact he's suddenly alive (which can be fixed), however this did remind me that when he first arrived in the future the game had removed his ghost appearance which I then turned back on with CAS, this could be what was causing the game problems

also i have re-installed traveler to prevent this happening in the future

Yes, that would have caused it. I wouldn't have thought that would work but I'm glad it resolved the issue.

Thanks very much for your help, hopefully with the mod travelling won't cause any more problems.