Rename function doesn't work on XCode 5.1

Question

i am using XCode 5.1 on Mac OS X. but i have some problem that i can't press the 'Preview'button when i try to rename the variable i selected, first time it works ok, but next time i can't. because the preview button was disabled i don't know why? anybody know what's the problem?

Here is a screenshot:

Thanks.

Answer 1

To Rename you must give a different name. have u tried giving different name?