We have transitioned the Bug Tracker to a new tool called Redmine. All existing bugs were migrated along with all existing users. If you had a user account on the old bug tracker, you will have to reset your password before you can post a bug on the new Bug Tracker. You do not need a user account to view the bugs in the Bug Tracker.
The new Redmine Bug Tracker includes a Wiki with some helpful instructions, I recommend that you give the Wiki page a quick read. Please let us know if there is anything needing improvement in the Bug Tracker Wiki.
Bug Tracker Wiki
Update 2021: If you are only registering now, please send a forum PM as below.