First, you need to verify that Cubase AI4 is compatible with Windows 10 (as there is about a decade between the release of the software and your current computer Operating System). There maybe features that simply will no longer work after that length of time. (You can contact Steinberg through your MySteinberg Account, or through www.steinberg.net

Second, the Motif ES does NOT use the Yamaha Steinberg USB driver 1.9.6 - that is the wrong driver.

Please go to the official Yamaha download site and find the correct driver for your computer and operating system.
Yamaha USB-MIDI driver version 3.1.4 for Windows 10

http://download.Yamaha.com

Select your country
Type in your Model Name: Motif ES
When the Search Results appear verify by clicking on the model number.

The Yamaha USB-MIDI driver will allow you record MIDI data only to your computer.

If you wish to record audio to your computer you will need to purchase an Audio Interface and a pair of Monitor Speakers.
An Audio Interface will allow you to send audio into Cubase with low latency. The drivers that come with a computer are not sufficient to do professional music recording. Typically, your audio interfavpce will come with or recommend a low latency ASIO driver, one that will allow you to play along with music. The drivers that come on your computer are only good for playin back - they cannot be used to play and record music simultaneously.

The audio interface will take incoming signals and route audio to your computer and to your Monitor Speakers. Please realize that an external audio interface (which is what you will need to record audio) will not come through your computer's sound system... The external audio interface replaces your computer's current sound system.