I am trying to make a inner track for a cog wheel (the cog teeth on the inside of a ring). I found and used the tutorial of nicu's. However, one object is not a path and a boolean operation can not be performed. I don't understand but would very much like to. Am I the only one with this problem?

Is one of them a circle? Do object > convert to path on it and try it again.

No dice.

Object to path, object to pattern. I tried it on cogs and circle both. There is still one path too little to perform the operation. As if circles would be troublesome, I swapped it for a rectangle. Same problem persist.

Update!

I seem to be able to get around things by using the "edit by nodes", instead of the "select" mode.