MacBook Air 2015 will not recognize LG Slim Portable DVD Writer

I have an LG Slim Portable DVD Writer that my MacBook can't find for some reason. I remember it working fine previously; the first time I plugged it in today, it read the disc & popped up on the desktop but stopped working when I ejected the disk for another. Now it can't see any disc I use. I have cd's visible in finder settings & usually devices will show up on my desktop as well. Does anyone have any suggestions?