Custom Application Keyboard shortcut for Safari not always working I uninstalled Flash a little while back, and installed Chrome as a back-up for when I hit something in Safari and want to see the Flash. I have the "Show Develop in Menu Bar" preference set, and created an Application Keyboard Shortcut for Safari, to Develop>Open Page With>Google Chrome. The shortcut I created was ⌘ + K. And it works!

Well, kinda. It seems like every time I quit and restart Safari, the shortcut stops working. But once I navigate back to Develop>Open Page With (I can just cancel when I bring up the menu, I don't need to select anything), the shortcut works again.

Any way to make sure it always works?
This is a known “bug” which I don’t know if Apple will ever consider a bug. 

The problem is that the list of browsers is generated “dynamically” each time you click on it (or at least the 1st time after Safari has been launched); the reasoning behind this is that different users will have a different set of browsers, so the list cannot be hardcoded. So given the above, the shortcut fails to work until the list has been “generated” by Safari. This occurs when you display the menu. 

A possible solution would be to use Automator and create a service that opens the current safari page onto Chrome. But that’s beyond the scope of this answer.

TLDR version: There’s nothing you can do other than file a bug report at Apple if you want to stick with the same shortcut technique. Alternatives involve Automator.