Sims not being able to return home from traveling is a known bug. It's a common bug and happens for various reasons. This bug comes from World Adventure and affects all kinds of traveling (China, Egypt, France and University. The only known "fix" for it without using mods is to go back to a previous save - Before traveling.
It's best to use Save As, give it a similar name just before traveling. That way if this bug appears there is a previous save to go back to.
Go Back to a Previous Save
http://www.carls-sims-4-guide.com/forum/index.php?topic=20732.msg433992#msg433992Reset Town, Individual Sims and/or Evict Household
http://www.carls-sims-4-guide.com/forum/index.php?topic=20732.msg401812#msg401812There are two mods that help in fixing this bug
Nraas Debug Enabler - May help "reset" bugged/glitched/invisible Sims
http://nraas.wikispaces.com/DebugEnablerNraas Traveler - Helps fix issues with going to the future, vacation, University, etc.
http://nraas.wikispaces.com/TravelerIf you want to read more on this bug, and more troubleshooting tips, please see links below:
Missing Sims and empty UI when arriving in vacation town
http://sims3.crinrict.com/en/2011/03/bug-missing-sims-and-empty-ui-when-arriving-in-vacation-town.htmlSim can’t return home from University
http://sims3.crinrict.com/en/2013/03/sim-cant-return-home-after-graduation.htmlSims 3 University-Sims stuck at school and won't go home
http://answers.ea.com/t5/The-Sims-3/Sims-3-University-Sims-stuck-at-school-and-won-t-go-home/td-p/730706
Original post below: (Updated to give tips to help with the travel bug)
Hi, lately, whenever I've had my sim travel, it seems that 100% of the time, the home world would not properly load again when my sim came back home. None of my sims in that family could go to work/school either. If they tried it would give a message - "starts in 1 day"
I went over to NRAAS and asked over there about it. I was advised to install the Debug Enabler mod from them, then immediately after my sim returns from traveling, go to city hall and choose nraas/debug enabler/options: city hall/sim/fix homeworld. When you do this, then everybody will be able to go to work normally.
