On a Macintosh, if LibreOffice is set as the default application for MS file types, opening a MS file with LibreOffice will only work if the mouse is moving. How do I correct this behavior?

After configuring LibreOffice to create Microsoft Office files by default (.docx, etc.), and configuring OS X to have LibreOffice handle such files, when a .docx file is double clicked, it will not open until the mouse is moving. Why? How do I fix this strange behavior?

I do not have such issue using v5.1.0.3. What version do you use? You may just want to update it to the latest version.

I have the exact same issue on multiple Mac’s runnning El Capitan and Libreoffice v5.2.3.3 (and earlier versions). When you right-click a spreadsheet (eg blabla.ods) and choose open from the OSX context menu, you see the Libreoffice icon showing up on the OSX dock and nothing happens (even if you wait a minute). When you move the mouse the libre office window appears. Same when you double-click a file.Very, very, weird behaviour.

I too I have the exact issue on Mac El Capitan with LibreOffice version 5.2.5.1

Same here, with Mac High Sierra and LibreOffice 5.3.6.1. It’s been like this for as long as I can remember! Certainly not a fatal flaw, but definitely a bit weird.