This message was posted on behalf of Intel Corporation
That's a weird issue, I ran the example code of communication between the host and the MCU, and I sent a message of 50 bytes without problems (Look at the photo), as you can see in the photo I sent it a lot of times without errors.
So, I'm not sure why you are getting that error. Are you using the latest Edison Image? Can you give me more details about your problem to help you more?
I will be waiting for your answer.
Have a nice day.