Hey Ive been updating about 20 + websites to the new k2 v 2.10.3, I have run into a routing / SEF issue with the recent upgrade, if you are using the K2 Tools "Category List (menu)" as a sidebar menu or something for a blog, or news articles, also for when using $this->item->category under any of the K2 itemlist templates.
all your category URLs will be giving 404 CATEGORY NOT FOUND.
The Urls will change from these between the versions:
v 2.9.0 = "blog/content/subcategory"
to v 2.10.0 - 2.10.3 "blog/content/blog/subcategory"
it seems to be adding the parent category in twice.
Could someone look into this.