crwdns2893792:0crwdne2893792:0 s.whas ,
check the black plastic assembly that gets pushed down when you lock the jar. It has two stick up tabs, one at the top of the jar and one at the bottom. On my ninja, this piece runs down the handle. If can get out of place so the black plastic tab at the bottom does not press down enough and does not signal to the machine that a tight connection has been made.