Hi.
Let's say, we have a simple forum like:

Code:

Category 1: Topic 1: Message 1
Category 2: Topic 2: Message 2

If I open the main forum block, then navigate to category 1 and open the Topic 1, I'll have correct path in breadcrumb like:

Code:

Index > Category 1 > Topic 1

And all messages in Topic 1 will be marked as read.

BUT, If i turn on the notification and someone replies to Topic 2, I'll get a direct link in e-mail to it like:

Code:

http://www.nowhere.com/forum/message/3.html

But, this topic isn't marked as read and in the breadcrumb I'll still have

Code:

Index > Category 1 > Topic 2

because I was in Category 1 as in the last category and now I opened the direct link.

It is because you are still in the browser and logged in to typolight while you click that link. When you click the link in the mail while you are not already in the browser (this might be the most common case) it would work.

The issue is known, but there is no solution yet.

That's right, i can see the last visited page in session variable, but it's quite bad behaviour, there's a block with neewest post on my home page and when clicking on the links the breadcrumb confuse.