The most likely cause for this error message is that your bill template will include an image (eg: company logo) that is no longer in its saved location, or the access to this location has been denied.
Ensure that your image is still available and the location it is saved in is fully accessible.
If you are unsure if your bill has an image and you have the access required then:
Open Advanced Report Creator.
Find the bill template.
Open the Alternate Layout.
Double click on the image.
The field is the image selected.
Click on the Choose new image button that looks like a calculator.
This will show you the image and location it is saved in.
Try to go into the location, see if you can open it.
See if the image is still saved there.
If the answer to either of the above is no then the location needs to be made fully accessible, or the image needs resaving in this location.
If none of these examples are the issue, then please raise a new case online and reference the title of this article.