One of the problems that I think everyone runs into is an empty tool path. The problem might be a lead in lead out error or a collision message. The problem is the messages are not clear as to what is causing the problems.
I suggest that the software draw the invalid tool path and highlight the problem area to help the user visualize what is wrong. If its a lead in lead out error it might only be the lead out that needs to be adjusted but with the messages given make it hard to figure out sometimes just what is wrong.
