I got the email access OK, thanks.
The problem is a minor one that will only effect a few users. I need to spend more time checking to see if it is worth fixing, but I suspect not.
The solution is very easy. Ignore the blank home page; login and go to Administration > Family trees > your family tree and click ‘save’/ No need to change anything, just click ‘save’. Repeat fro any other trees you have.