I have been trying out Lyx on the Mac over the past week, and have a repeated problem setting preferences. If I try to apply or save any preference from the Lyx menu while there is a document open, a blank white box appears (as if the system is trying to show me a message of some sort, except there is no message) and the program freezes. This is repeatable on both my laptop and iMac running MacOS 10.12.5, and the only way out is to force-quit the program. I eventually learned that setting preferences only works if there is no open document.
Additionally, if I try to change a key binding that is already assigned to another function, the program notifies me, and asks me if I want to reassign the key — but if I say yes, I am dumped out of preferences and nothing is saved. These look like bugs, but any information or assistance (am I doing something wrong somewhere?) would be helpful. -David
