I cannot log in to this forum when the browser is in “private” mode. I am using Safari on macOS 10.13:
- File -> New Private Window
- Click on the “Log In” button
- Enter User and Password, click “Log In”
There is no error message (such as a wrong password), but I am not logged-in. The forum's start page is presented again with “Sign Up" and “Log In” buttons.