The old SOTA website didn’t have any accounts for users.
You couldn’t log in because there was nothing to log in to.
The new SOTA website does have accounts for users.
As you didn’t have an account before on the old website, it can’t be moved to the new one.
Therefore you have to create a new account.
The SOTA website www.sota,org,uk is not the reflector (the web site you are reading now) and is not the database where your activation and chaser logs live and is not SOTAwatch where spots and alerts live. The fact there are 4 does cause confusion.
4 websites == 4 accounts. You can set the accounts have the same username&password if you want but there are reasons why that is often not a good idea.
Why we have 4 websites (and accounts) is consequence of how the services were created in the past. It would be nice to have unified logins so your account is good for all sites. We’re not there yet.
Go back and read the third comment before yours Karl, from Jon GM4ZFZ.