We’ve migrated to Discourse recently so there may be teething issues…
Your old username and password should still work (although if you had a space in your username, you need to replace that with a “_” e.g. “Alex Smith” becomes “Alex_Smith”).
If you get stuck, you can email me: firstname.lastname@example.org
Logging in gives you access to “Members Only Area”, which is where about 1/3 of the posts are located.