If your students are receiving a message stating "Your teacher didn't expect you to be here. Please ask your teacher which lesson you should be on." if there are lessons or units marked as hidden for their section.

You can un-hide units in full from https://studio.code.org/courses/csd and https://studio.code.org/courses/csp for example. 
  
If you are confident you've un-hidden units or lessons from students but they are still seeing this message, we would then recommend the student take a look at the bottom of their homepage. This area lists all of the sections they are in, and the names of teachers who own each one. 
 
You can use this info to double check these factors:

• Make sure the affected student isn't in several sections of yours, which would each have separate hide/ show settings.
  • Units need to be marked as not hidden in every section a student is in, for them to access it
• The student may be in some other teacher's section, who has marked the content hidden from them. 
  • You'll then need to get in touch with the other teacher(s) to request they either remove the student in question from their sections, or request they un-hide content from the student

For more information and troubleshooting, read more about this feature here.

If you still need assistance, please reach out to support@code.org with the following information:

• The usernames of the affected students
• The email address associated with your teacher account on Code.org
• The units/lessons that are hidden for these students