Here on Ask Ubuntu, we have a page dedicated to explaining what is on- and off-topic: http://askubuntu.com/help/on-topichttps://askubuntu.com/help/on-topic
Nowhere on that page does it mention that problems of this type are off-topic. So either that help page should be updated to say that such problems are off-topic, or the flag should be moved to a different flagging section.