By default, when you install flash player video, the hardware abstraction layer is not installed. This might cause issues when you want to play video (for example in Amazon Prime). You will see a message saying
flash version isn't supported or
Sorry we are unable to stream this video. This is likely because your Flash Player needs to be updated.
The only way you can get around this error is to install this hardware abstraction layer (hal) by using the folloing command:
sudo apt-get install hal
Once the HAL library install is complete, close all Internet browsers and remove the current cache and data:
cd ~/.adobe/Flash_Player rm -rf NativeCache AssetCache APSPrivateData2