One of the guys at work did the upgrade. He asked for some help and I realised he was not running upgrade.php via the browser. We then ran it through the browser and it got through to the end successfully.

Unfortunately we can now no longer log in. The log in page simply re-appears after we enter our credentials (and also tells us that the board is closed). Even more unfortunately, somehow the backup of the previous UBB folder (under Inetpub) lost most of its contents - so we cannot revert back to that. I tried to run upgrade.php again but it advised that the upgrade was already done.

The database looks ok (the user table still has the administrator user accounts).

Any ideas on how to fix this?

Thanks, Paul