A document merges fine when selecting Same as template, but when outputting to a PDF, the following error appears: "One or more documents failed to convert to PDF."
A common reason for this is a custom font is being used somewhere in the template. While this doesn't cause issues when merging Same as template, it will error out when converting to PDF.
What to do
The resolution is to Contact Support to get the custom fonts uploaded. Customers will need to provide an .otf or .ttf font file.