I posted about this a few months ago but am now having the same problem again. My hosting control panel is accessed at /admin and so I can't access the silverstripe admin. I fixed this by edited /cms/_config.php in the Director:addRules function by changing it to siteadmin.
I have now updated my site to 2.3.1 and this no longer works. Can anyone help me with what to change to get this working?
Thanks