Lab 2b

That's covered in the Help FAQ. Here's what it says:

Something is went wrong in Step 81. That's where you were supposed to create that Meeting ID field to connect your Meeting Attendance object to your Meeting object. For whatever reason, that connection didn't get set up properly.

So, to fix it, go back to your Meeting Attendance object and delete Meeting ID and then use Step 81 to add it again, this time making sure follow the instructions carefully so you connect Meeting Attendance to Meeting. Then start over again at Step 104 and when you get to Step 112, Pitch should show up properly.