Chosen Solution
I haven’t had this problem before. I am using an Android File Transfer App but my MacBook Pro 17" won’t recognize my phone via USB. I recently installed a new 1T hard drive but that shouldn’t be an issue (or is it?)
First reinstall the latest version of Android File Transfer, download here and follow the directions. That failing, replace the cable and examine the ports for debris. https://www.android.com/filetransfer/