I am brand new to vector graphics and in the middle of creating my first illustration. I got a handle started for a coffee cup I'm drawing, and I want to "erase" part of it using an overlaid object and the boolean operation "difference". The problem is that none of the boolean operations have any effect on this object. I can create other objects and play around with "difference" and "division", etc., and they work as they're supposed to. On this particular object nothing happens. What might be the possible reasons for this? Thanks in advance.

Is the object a group? Or locked, or in a locked layer?

I tried the object as a group and as separate objects as well as object-to-path. I didn't create any more layers, but perhaps I inadvertently locked the object since I wasn't aware of the locking mechanism or how to use it. I actually ended up redoing the object from scratch and the boolean operations are working fine on that newer object. So, in case this happens again, how do I lock/unlock an object? Also, should boolean operations work on a group and another single object?

No boolean operations can't work on group + single object.

Unlocking an object is a pain, it's recommended you put the object in a separate layer and lock the layer because it's easier to unlock. viewtopic.php?f=22&t=48