They were probably disabled by a custom menu. See if you can change the menu to the standard menu (look under the tools menu at the top) Tools > Custom Menus > [FileMaker Standard Menu]
For example, if you look under the edit menu and Copy is grayed out, then the keyboard shortcut wont work either (unless it's reassigned in a custom menu as something else)
This is a known issue with OS 10.10.
For More Information see: Shortcut for Layout disappear
This is one of many acknowledged bugs that can be found in the Known Bug List thread here in the Report an Issue section of the forum.
It can also be downloaded as a database file from: https://www.dropbox.com/s/jt09b82i0xijbu3/FMP%20Bugs.zip