Some of the exercises here use AlignDetectors, which is now deprecated and should be replaced ApplyDiffCal and ConvertUnits (talk to Diffraction team).
Maybe make clear at the top of the solution 1 page that all the data can be found in the TrainingCourseData (from Downloads page)
Check all solution scripts run! e.g. solution 2B is missing the from mantid.api import AnalysisDataService as ADS import
from mantid.api import AnalysisDataService as ADS
import