I'm currently fixing up a model which has nearly 700 open edges (open seams disguised as ordinary lines of vertices), and I'm using the "STL Check" modifier to find them. The only problem with this method, ESPECIALLY in my case, is that I have to keep toggling between STL & Editpoly EVERY time I want to check an error and…
Not sure which version of Max you're using, but 2010+ has a feature called 'Xview' which I've been using in place of STL check. It's a lot more interactive and visual, and also selects the subobjects of whatever filter you have active (including being in editable poly). Click the + sign in the upper left hand corner of the…