Problem
The section for datasets has incorrect links for downloading data for working independently.
The section that has incorrect data links is http://docs.inasafe.org/en/training/socialisation/datasets.html

Solution
Update url to access the datasets.
The url that is able to access data is: http://data.inasafe.org/TrainingDataPackages/
It looks like a spelling error on the request.
The requested URL /TrainingDataPackages/Indroduction To QGIS.zip was not found on this server.