Since the X-mas update on Friday a number of users myself included have not been able to even login to the website.

Symptom :- Click Legacy login and enter details and click ok, the system will authenticate the details ok but the big blue button will remain as "Log in" and not change to "Play"

This is a new problem and it caused by a missing cookie that can be created by the other login methods.

Workaround :- Click the blue facebook login button and when the page redirects to facebook click not now, it will redirect back to TSO, you will then be able to use the legacy login as normal.

Loging in using an ubi account will also create the cookies, just don't use the registration part after the ubi login succeeds as that will create a new TSO island at lvl 1, just click cancel registration at that point (see the ubi account migration stuff)

NB Make sure your not logged into facebook if you have it before trying this.