Hi Ronald, it seems that there is a new restriction on the size of the images in the newer Jakarta version. They are stated here from what i have found: HR Document Templates

It basically states:

• The logo image to use in your header. The header image can be a maximum of 50px high. If your letterhead includes a logo and text, ensure that the logo image includes the text, as you can only configure the image in the header.
• The logo image to use in your footer, if applicable. The logo image can be a maximum of 15px high. You can configure both an image and text in the footer.

Also the way they accept images has changed from the previous versions. Take a look at the HR plugins example, but doing a direct image works better like:

this.headerImage = instance + "Print-logo-workorder.jpgx";

I ended up sending in the image like this:

 var headerId = gr.u_header.getDisplayValue() ? gr.u_header.getDisplayValue().substring(0, gr.u_header.getDisplayValue().indexOf('.iix')) : '';

 this.headerImage = this._getTemplateImage(headerId);

And the function invoked looked like this:

   _getTemplateImage: function(attachmentSysId){

// gs.addInfoMessage('Going to add image of ID= ' + attachmentSysId);

if(gs.nil(attachmentSysId))

return '';

var imageAttachment = new GlideRecord('sys_attachment');

imageAttachment.get(attachmentSysId);

var binaryData = new GlideSysAttachment().getBytes(imageAttachment);

var base64Image = GlideStringUtil.base64Encode(binaryData);

if (!gs.nil(base64Image))

return '<img src=\"data:image/png;base64,'+ base64Image +   '"/>';

else

gs.info('Issue found with getting the image');

return '';

},