Invalid Inline Image Name
Add-on discovered an inline image with unsupported characters in its name. In order to make sure inline images are processed by the add-on and displayed correctly in various email clients, you need to rename the image.
Inline image names can contain only US alphabetic characters a-zA-Z , numbers 0-9, underscore _, dot ., dash - , parentheses () and a blank space character.
It is easy to fix, follow these steps:
Remove the image in question from your draft
Rename the image on your laptop or in Drive so it contains only allowed characters
Re-insert it back to the draft as inline image
Start merge process again
A few valid examples:
✅ Inline Image.png
✅ My logo.png
✅ image (1).png
A few invalid examples:
❌ Promoción.jpg - the name contains ascended character ó, replace it with o => Promocion.jpg ✅
❌ image.jpg - the name contains square brackets, remove them or replace them with parentheses => image1.jpg or image(1).jpg ✅