This is interesting:
I have a simple script:
Set Variable [$layout; Get ( ScriptParameter )] Go to Layout [$layout] Exit Script 
Script parameters are passed such as "Dashboard", "Customer", "Project", etc. And it all works fine. Today I added an Admin layout and when I click the button to navigate to it, I get a 105 error (Layout is missing). The passed parameter and the layout name match.
Now, if I put this condition in:
If [$layout = "Admin"] Go to Layout ["Admin" (ADMIN) End If
it works. That doesn't make sense to me, but it does work.
So the next thing I tried was modifiy the layout name from "Admin" to "Admino". I changed the parameter as well to "Admino". Now,
Go to Layout [$layout]
It seems like "Admin" is a reserved word that doesn't work with variables in Go To statements. This is total conjecture on my part. Anyone have a better explination?