Getting a message about ultra sonic interference . Then when I return the red light is on solid on the back of the Mavic. Any ideas

I understand that the Mavic's ultrasonic sensors operate at around 40Hz. If your craft was flying anywhere near frequencies in this neighborhood, such as bass from music played through speakers, it can confuse the on-board sensors.

Hi there, could you please post a screenshot of the error message?  Was there any other abnormal performance besides the solid red light?