Uni Students Visit Darby's Den, Now Can't Return to Dorm

I'm very concerned. I was having a great gaming session today. My students began their first term, and I was able to play them all the way to having only two days left in the term. Since a holiday I created was happening, with one goal requiring water play, I took them to Darby's Den, where I could have them purchase a Water Balloon bucket.  Behind and below Darby's Den is an area that has two picnic tables, each with a BBQ. I had them BBQ up a meal, since this was also a goal. When it came time for them to return to Wyvern Hall, my Sims couldn't return. I'm going to attempt a game repair to see if this helps resolve the issue. Yes, I have mods, but I have to say, nothing changed after my hours of gameplay, so I'm hard-pressed to see where the mods would suddenly be running interference. They were all able to go to their classes. They were also able to go out to dine in Willow Creek and return. What the heck is going on? Wish me luck. I'm really not wishing to rollback and replay then entire weekend or more prior to the Term beginning.