My colleague is trying to detect Luciferase by Western blot and what she got is nonspecific binding - figure A (?). On fig.B she was using anti-His Tag antibody just to check if the sistem is working and what she concludes is that system is working but she is till not sure about fig.A.

Can someone maybe explain us what is wrong with her anti-Luciferase detection? Is the problem with blocking or with concentration of second antibody?