Got a new Macbook and my iTunes and Apple TV apps won't let me choose my old iTunes library

So my iTunes library is housed on an external hard drive. I recently got a new Mac. When I use the option+click on the Apple music apps and the Apple TV on the new computer and try to choose my iTunes its file, it will not open the library in iTunes. It asked me to "save as" and I choose the external hard drive. It is apparently trying to create as Music1 or TV1 but it doesn't work. I hope I'm explaining this so someone can understand and help me. I'm thinking that it's having a problem because my current iTunes library on my hard drive was created in an older version of iTunes. Is there anyway I can do this without having to create a new library and re-add all of my content? I have over 7000 media files.