It ran for me in 2012, renaming Layout1 tab to test in the active drawing.
It worked as above. No error message.
I'm confused what the OP is trying to do. If he's trying to change the name of the layout tab in the saved -test drawing, wouldn't he just use saveas to create the file, and then open the saved drawing with DBX, change the layout name and resave it? Or change the name in the active drawing, and then do a saveas?
For ronjonp's purposes, I'm pretty sure he's got what he needed from posing the original question at this point.
Forgive my reason for questioning you, Cathy; I thought it was understood that the renaming of the Active Document's Layout Object was not the intended goal, but as ronjonp has already clarified, instead to rename a Layout Object via DBX... That said, the creation of the *-test.dwg was for testing purposes only... Presumably, the intent was to iterated a directory of other drawings (not saved as from the active document). Just speculation on my part.
Cheers
