I previously had LibreOffice installed on my MacBook Pro and I chose to update to the most recent LO release (4.2.8) and now it says it can't verify the program because my computer settings don't allow for programs that aren't from the App Store. I've updated countless times and have not had this issue until this update.
The problem is known, and it’s due to a change in Apple’s Gatekeeper. We have already changed LibreOffice so that it complies with the new Gatekeeper, but you’ll need to upgrade to 4.4 to get it, as it wasn’t backported to the 4.2 series (the change was big and deemed too risky to backport). *** This bug has been marked as a duplicate of bug 84352 ***