The app. couldn't locate a CD or DVD Drive in your device. If you use an external (or portable) CD/DVD drive, make sure that you have plug it in a USB port of your computer. Also, check that any power cord that the Drive may needs, is connected.
The app has succefully identified your Optical Drive. Now, in order for the app to be able to read and play your CD/DVD contents, you must explicitly give a permanent access to the app for reading your Optical Drive. This is only needed once! Press the button below, select your DVD folder and click on the button "Select DVD Drive".