Invalid canvas height

I am using Mocha Pro 5.6.0 on a Mac. I am triggering Mocha from After Effects with footage that is 3840 x 2160. After I hit OK on the Mocha import screen the footage opens with the error message “INVALID CANVAS HEIGHT”. I only get this message on the initial import; it doesn’t show up again.

Is your Mocha set to be expecting 360/VR footage that should be 2:1 ratio? That’s the only reason I would expect to see an error like that…