If you are following someone else's link look carefully at the host that cannot be found - people make lots of errors writing web pages as well as directly typing URLs into their browser. The Web is probably too busy at the moment. If the URL is outside the UK then think what timezone it is at your destination. For example, if the Web site is in North America then by the afternoon it gets very busy. Try it again in the morning while the Americans are asleep.
Canadian sites end in .ca .
The store contains the most frequently loaded pages of all people using the cache. The page may have been moved or renamed. Edit the URL removing the last part. Repeat until you reach the server name. In this case trying to find a list of members of the department would be a good start.