My external dvd drive also wont play on my chromebook. So I just rip and convert the DVD to HD video to Chromebook. Maybe you can do so. Just follow below steps.
Step 1. Download and Install Handbrake
First, you need to download Handbrake and install it on your computer. Once downloaded, you'll be asked to install the program. Follow the directions on your screen and you'll be fine.
Step 2. Import DVD File
Open Handbrake and click on the "Source" button at the top left. Select DVD from the drop down list. Then browse for the location where your DVD is located. Select the DVD or the folder, and click "OK".
Step 3. Change the Destination Settings
Once you've chosen the source, the software will automatically ask you to select the destination. The way your picture and sound quality will turn out in the resulting file depends on the settings you choose in this step. We click "Browse" for our file Destination, choose a location for our new file, as well as give it a fitting name. We'll go ahead and save the file in the same location as our source and click "Save".
Step 4. Output settings
Go to the Output Settings and choose MP4 as the output format.
Step 5. Click Start
Once you've chosen the source and destination settings, you're pretty much set to go. Just click on the Start Encode button and the program will do the conversion for you.
Handbrake is easy to use, risk free, and we are able to achieve very desirable results, simply using the default settings.
For more details, check:
How to Play DVD on Chromebook