Chosen Solution

Suddenly my USB 3.0 external drive won’t let me save or copy out document. Working on a music video which should be out on the 20th of April. I shut down my laptop earlier after finalizing my edit. I tried to open it later and was not granted access to project because of my external drive reasons. I looked everywhere online with no luck. Please assist me how I can resolve this issue and what caused my external drive to stop working well. MacBook Pro Retina 2.8 GHz Core i5. Running MacOS High Sierra 10.13.4

First see if you can try a different cable. Second, try this on a friends Mac if possible. What brand of external USB 3.0 hard drive? Seagate or WD? If it is Seagate and under 2 years, some models have a free data recovery service due to the massive amount of failures in their products. Run your serial number to find out. Otherwise if this is a different Seagate model or other brand, you will have to seek a professional data recovery service to download your music video.