Can't travel back fom University

@_aiinsleyyy_123  The rules here aren't strict like on the official forums, but it's still better to start your own thread rather than post in an old one.  So I split your comment into its own thread, just to make things easier.

Hopefully you're continuing to delete the five cache files in your game folder in Documents.  They should be deleted regularly anyway, even in the absence of game issues.  While you're troubleshooting, be sure to delete them every time you quit, whether you saved or not.  You mentioned deleting the cache already, but make sure you get all five of these files:

• CASPartCache.package
• compositorCache.package
• scriptCache.package
• simCompositorCache.package
• socialCache.package

To repair a family tree, you need a couple of things.  The first is not only the MasterController base mod but also its Cheats add-on.  Then you can run a commd to remove parents (or children, or siblings), just to clean things up, and then add them back.  But this probably won't work while your sims are at University, because the second requirements is that the parent(s) to add exist in the world currently being simulated.  While the other cousin presumably remembers the aunt or uncle that's the parent of the glitched sim, I don't think the existence of that relationship is enough for the mod to find and assign that sim as a parent.

Regardless, it may be a good idea to remove the familial relationships from the glitched sims, and then repair the family trees once they're back home, if you can get them there.  Afterwards, you can use MC to reset those sims again, then use "save as" to rename the save (so you have a backup), quit (without saving, as a separate step), delete your cache files, and reload.

Before you try to send your sims back home, I would definitely recommend adding NRaas ErrorTrap, Overwatch, and Traveler to your mod collection, if you don't already have them.  ErrorTrap is a core mod, so be sure to get the version that matches your type of install (Origin, Steam, disc; if you're playing on a Mac, get the disc/1.67 version); the others are fine on either patch 1.67 or 1.69.  These mods together are the best way to prevent an error during the travel transition, although it can still happen.

After you add these mods, it's a good idea to reset the whole University town.  Click on City Hall and select NRaas > MC > Town Options > Reset Everything.  This may take a few minutes, depending on how many items need to be reset—in a homeworld, the number can easily top 20,000.  This will also reset your active sims.  Then "save as," quit, delete your cache files, and reload.

You've already lowered your graphics settings, hopefully to the minimum, but here are more steps you can take to lower the stress on the game engine:

• Aside from the cache files, be sure to delete everything in FeaturedItems as well.  This is just the store trying to sell you stuff.
• Don't login to either the launcher or Main Menu.  Even better, take your computer completely offline before launching TS3, as in, turn off wifi and/or pull the ethernet cable.  If you play through Origin, sign in and then put it in offline mode.
• Turn off the in-game shopping experience and the hidden object interactive loading screens, both in settings.
• Turn off memories too, although this helps the most at the beginning of a game, before sims' scrapbooks fill up.
• Empty out your sims' inventories as much as possible: a few items are fine, a hundred are not.
• Send your sims home right away, a few in-game minutes after loading the save.

You might have to try this a couple of times to get it to work, and it wouldn't hurt to reset your sims, quit, clear your cache files, reload, and reset them again, especially with ErrorTrap in the mix.