I am a competent computer user, with professional CAD and Adobe programs. I wont to get away from MS Word (it is such a donkey). I download LibreOffice and try to install. Drag LibreOffice icon onto Applications. When I try to launch LibreOffice I get a verification with a progress bar. The bar finishes, but nothing happens. After about 10 minutes, still nothing. I dismiss the static verification. I try to launch LibreOffice from Applications and it doesn't launch. The computer slows and seizes up. The The Finder doesn't work properly. I have to restart. I am using an iMac with: OSX version 10.10.5. Processor 2.8 GHx Intel Core i5 Hard disk has 1.71 TB available
*** This bug has been marked as a duplicate of bug 97530 ***
Had to resort to `xattr -d com.apple.quarantine /Applications/LibreOffice.app` in a terminal to be able to launch it.
See also : https://ask.libreoffice.org/en/question/64253/libreoffice-513-stuck-on-verifying-mac-os-x-yosemite-10105/