Hi Annelies,
While you can copy and paste images into our platform, for some reason, Microsoft Word is embedded with an excessive use of characters per image. This is why you may be hitting the character limit.
Unfortunately, the only solution we can propose is to save the Word Document as another format (ex. Google Sheets). Maybe a different format will have fewer characters used per image.
If a new format does not work, manually saving the photos and uploading them into the post seems to be the only option. I understand that this will take time. I wish we had a better workaround for this!