Bread crumb trail on forum topics

When you go into a forum topic now the bread crumb trail at the top of the page is missing.

The bread crumb trail used to be a "Forums" link at the top of the page for a specific sub-forum (which is still there) and then the sub-forum link at the top of the page for a topic, e.g. Forums >> General Chess Discussion. This extra link is now gone. 

Is this a bug or did it get removed on purpose?

If it was on purpose, why on earth would you change that? It is very user unfriendly. 

Exactly! This is ridiculous, if they removed these useful links on purpose.

The missing breadcrumb trail is consistent with the statements about the usability of the left-side menu.  That the breadcrumbs seem to come and go is also consistent with the statement about keeping the code simple.  I'm highly sceptical about both.

consistency is sounding like a bad word now ...

Consistency is usually a good thing, but the presence of the breadcrumb trail depends how you get to the specific topic (sometimes you have a usable return navigation path and sometimes you don't), which is poor usability, just like unlabelled icons are poor usability.  Consistency with ideas that are themselves broken is a bad thing.   

I wondered what had happened to the links - hope they bring them back!

Apparently it was a bug, because the breadcrumbs are back!

A bug would be the wrong text or a broken link.  Present/missing on pages where the link should always be is likely to be deliberate.