Transport out has not been set

I’ve was banging my head against the wall all yesterday evening trying to work out why Axis2 was erroring out with ‘Transport out has not been set’. All my searching for similiar problems was returning the same mailing list entries, replicated all across the internet, none of them having anything useful. For me at least (and some of the problem is that it can be caused by more than one thing), was that I’d commented one URL out when I went home and created my home one, without including ‘http://’ on the front of my URL.