I find as mentioned here there is some sort of conflicting setting and I always keep reviewing settings and changes or delete and start over with new operations until the problem is fixed. From what I see some of the safe plane and transition options and settings have some sort of hidden error in the data or input field. One error I see all the time is the tool number and length corrector can show correct setting in tool window but have different numbers showing on lower left tool data tab.
They still have not fixed that? wow I run into this 10 seconds after update. Mentioned it to tormach and they sent me video on how to not locate part in mill table.
little giggle because I never had that problem from day one when I started learning this program couple years ago and I use full fixtures, machine is visible for all parts on all operations on all offsets on all sides right down to works stops and tool holders. I try to use the cam tool to its fullest and I can say it has saved me with less tool damage and I don't ever mill AIR
I have avoided online updates as they have caused me problems in the past and still run only the oem disk release. Wish I could keep updated with out fear of major problems or new and different errors or quirks to work around.
edit : might be brave someday