My laptop has both Kubuntu 14.04 and Windows 10. My KDE version is KDE 4.13.3. I use Kubuntu 14.04 daily. No idea when this happen however this past week I noticed the following:

This only happens with / in Favorites when in K Menu Classic Style, if I right click on an app (in Favorites only), instead of a drop down with options like "remove from Favorites", etc, it launches the app as though I left clicked.

If I do the same after having changed K Menu to "Switch to Application Launcher Style", all is well.

Additionally, in Classic Style, if I right click on the Favorites folder, I get nothing like the small window I get of other folders, such as Settings, System, Multi-Media, Utilities, etc.

Right clicking on them, for the most part gives the option of Add to Desktop / Add to Panel. So there's the problem.

Thank you

I can confirm what you are seeing. Kubuntu 14.04, KDE 4.14.13 (Kubuntu backports PPA).
With the (classic) Application Launcher Menu widget, right-clicking on most entries brings up options for adding the item to various places. Right-clicking on the entry for the Favorites menu does nothing, right-clicking on one of the entries in the Favorites menu launches the item.

Thank you. Confirmation because you have the same anomaly?

Confirming that I can reproduce the anomaly. I prefer the other launchers which present the favorites in the main/default view. In those you can right-click on items in the favorites view and get options such as Remove from Favorites, Add to Panel and Add to Desktop. Presumably those options should be available in the menu launcher as well, but are missing for some reason.

I wonder if the anomaly is derived from the fact that the Favorites submenu is kind of separate from the general menu structure, needing special handling in the menu launcher. As such it may be that the right-click menu is just not implemented there.

I also wonder if this is fixed in Plasma 5.

Thanks. Could be. I'm just a simple user. But it seems to me other than two different Menu styles, the actions performed within Favorites (per app) would remain constant. For example, if I desired to remove an app from Favorites, I shouldn't have to switch to the other Application Launcher Style to do that. As you suggest, perhaps it's always been this way. I just can't recall.