When selecting a file to open whose filepath is too long, Bluebeam does nothing. No alerts, no advice, nothing happens, it just sits there. One potential fix would be if Bluebeam recognized the event and moved the file to a temp storage directory closer to the user's root directory, allowed for normal operations and use, and then pushed it back, if saved, to the original filepath location. Barring this corrective new feature, Bluebeam could recognize the fail-to-open-file event and popup a message advising of a means to open the file in another way is to move it to a folder location having a shorter filepath, such as the user's desktop.
