I have my MBP OS X 10.10.4 beta 5 security setting such that I cannot open applications from unidentified developers. This morning I wanted to change some videos from .avi to .flv so I launched Handbrake. I was in dual pane mode with the applications menu in one and Movies in the other. Handbrake was not identified so I got an error message. Then when I clicked Ok, TotalFinder 1.6.27 dropped out of dual pane mode and closed the right most window. TF continued to run just the dual pane mode was cancelled. This seemed to be reproducible but now that bypassed security and ran Handbrake, I can no longer test for the problem. Is this a feature or a bug?