Issue while using BoxCutter

Question Modeling

Hi,

I don't know if it's ok to ask questions about add-ons. If that's the case, just don't mind me.

I'm using BoxCutter to create some hard surface models and I'm following a tutorial and of course things don't go as planned :) While I'm trying to cut a cutter, I get some ugly distortions and shading. The problem is that I don't fully understand all of the stuff this add-on does in the background and so I have no idea what to fix/ where to look. 

I saw that sometimes using the knife tool helps. Again, don't know why, just something that people do to fix these kind of issues. Maybe that new cut is interfering with the bevels next to it?

I will go ahead and upload the file, just in case there is a possibility to get help.

boxc.jpg