For anyone running LyX 2.2.0 under KDE (or using a KDE-based window manager, or anything of that sort):
There is an annoying new feature, KDE's "accelerator manager", that automatically adds shortcuts. This causes conflicts and so forth in many Qt-based programs, when those programs are run with Qt5. If you are experiencing this issue, please see
http://www.lyx.org/trac/ticket/10261#comment:16 for a workaround. Richard Heck