Snapshots not creating an archive

I have installed Snapshot and configured to run manually on the database. When I click run now, I get feedback that it is scheduled to run. I wait a bit for it to get into the queue, but it never gets created. I am running the latest version of WordPress and Snapshot 2.4.3.

I have never run it on this host before and suspect it may have something to do with the host environment. Are there requirements that you can provide so I can ask them to allow Snapshot to run?

Thanks