"Import to my maps" file converting error

[jcre...@gmail.com]

Hello - 

I'm trying to upload an image to 'my maps' and the file appears to upload, but then I receive an error: 

Something went wrong when converting the file.
Make sure you are uploading a valid file and try again.

Best guess, I don't have a valid file - but I can't seem to find any information about what file types are valid!

I've tried several different high-res (4800x6k) .jpg images, but perhaps TIFF or another format is required?

Can anyone provide some insight?

Thanks!

-JC