Proof that the problem was solved, finally!
This post is for those who play The Sims 3: University and when their sim goes back to university, the load screen just stands just before the finish and it never completes. This happened to me. I even let it stand for about 10 hours and it never completed. I was about to give up and reset the whole neighborhood when I found this advice by Summerrainajk on the Sims 3 forum. I tried it, and although I did not get the same message, it worked!
What I did was before leaving for University, I pressed F5 and chose to edit town. Then I selected the University town in the upper left corner, and moved a house there. I am not sure it was necessary to go that far, I think just adding a new bookshelf in the library is enough, but since I did not get the message that all actions would be canceled, I went all out. Then I saved and returned to my game, and now my Sim went back to uni without problems. I was actually surprised by how fast it loaded, so perhaps there had built up some slowness during his earlier visits as well.
Hopefully most people will find this on the Sims 3 forum, but you have to log in to read there, and I suppose many people will have lost their password or may even have changed their email address, in which case they can’t recover the password. When I started the Chaos Node, I had an email address given by my Internet Service Provider. Then they were bought up, and you can guess what happened. So any place I did not remember to change my email address in time, or where they did not have a policy that allowed you to change your email address and keep the same account, I was locked out. Hopefully I can help someone this way. But it is all thanks to Summerrainajk, and if you share this solution be sure to credit them and not me!
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Oh, and one bonus not-really-cheat for Sims 3 University Life if you also have Sims 3 Seasons: The super Simmunity lifetime reward, which is fairly cheap at 7500 points, protects against nausea as well as flu and allergy. You can get freebie chocolate and soda at orientation, as much as you want, and they will feed you quickly when you are hungry, give you a sugar high positive moodlet, but without the nausea moodlet you would otherwise get. So it is a great snack! ^_^