I have "Home" menu linked to "K2 category".  It's exactly what I want.  

 

But if I try to log in while it is in "home/k2" page  I get a 500 error -  can not find "layout=category" or "latest"

 

But if the page is not a "home" page with "k2 content", say a regular joomla article, login works just fine.

 

Please advise.  Thank you.