url slug wrong on portfolio page now it's broken

Somehow there is an extra line at the end of the url for my portfolio page and it won't work. It changed the project pages to have // and it shouldn't have any but when I rename it it says it already exists and won't save. 

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Hey Tracey, if it's saying the URL already exists you might want to double check elsewhere to see if it does.

Have you tried taking the second '/' out and adding a '1' at the end of the slug just to double check that you can actually change it and it's not an error?