The reason, most likely, is that your scanned document is over our upload limit of 2 Megabytes. There are several options.

Reduce the size of the image to less than 2 Megabytes. This can be done using image software or reduce the resolution of your scanner.

We understand that some people simply don't want, or simply don't know how to do this and so an alternative is to upload a document written by you that states,

"I have completed X credits at the location during the dates XX/XX/XXXX - XX/XX/XXXX and have certificates proving this that are available upon request."

A large portion of health care CME has always been based on professional honesty.