One of our faculty members is attempting to copy content from one to another and adjust the dates and time when doing so. When they attempt to shift the dates during the course copy, they get an error that says "Couldn't adjust dates on assignment <assignment name>, and seemingly none of the dates and time for the entire course content were adjusted in the copy. I have attached an image of the error.

Any idea what is happening? There doesn't seem to be anything special about any of the content to prevent it from copying.