Web site - unable to logout

I tried to log out by clicking the "Log Out" in the page header. I am redirected to "https://portableapps.com/user/logout"
That page says Access denied - You are not authorized to access this page.

The Back button shows that I am still online. I'd give a screenshot if I see how to upload it.

Firefox 92.0 (64-bit) on Windows 10.0 Build 19042