I'm not sure the reason, but perhaps you can upload your part file for others to try to replicate and remedy.
Not even Power Trim?
So, power trim didn't work: I forgot about the options under "trim". It looks like the default is "power trim".
but the corner option did work...but I this still doesn't answere the question about the split entities error message. Any thoughts?
Any idea why power trim won't work but corner trim would? Has anyone ever seen this "split entities" error? Why would it be "unavailable for splitting nor for trimming"?