The following was written by Library and Archives Canada:

After a tremendous take off for the launch of the 1931 Census on June 1, traffic increased rapidly. Our system started showing signs of slowing down, followed by difficulties with loading images. Unfortunately, this affected our users’ online experience, and we apologize for the inconvenience. We are as disappointed as our users, given the tireless work that went into preparing for the 1931 Census release and the anticipation around that release.

We are actively working on finding technical solutions and testing is ongoing.

While we do not have a timeline to offer at the moment, giving our users a great online experience with the 1931 Census data is our top priority.

Thank you for your patience.