KDP says “Unsupported fonts are used in your file”

If KDP's Print Previewer stopped your PDF, it found a font it refuses, and its message names the font: “Unsupported fonts are used in your file. Please create a new interior file with "LucidaGrande" replaced.”

The font can be one you never chose. Embedding it does not help: the message asks for it to be replaced.

The short answer

Open the PDF's list of fonts, find the one KDP named and see which characters use it: it may be only a symbol, a bullet or a space. Replace it in your Word file with a font that has those characters, export the PDF again and check the font list once more. Our free PDF checker names the font with its pages and characters.

Which fonts KDP refuses

KDP's help does not list them. It says “Fonts that cause problems during production are no longer accepted”, and that the file is refused when it arrives: “This is not a decision-based rejection.”

Every report of this error we read on KDP's forum in 2026 names a Lucida font: Lucida Grande, Lucida Sans Unicode or Lucida Calligraphy.

Why a font you never chose is in your file

A word processor sets a character your font does not have in another font, without asking. We tested this on 6 November 2026. In Word for Mac, version 16.78, a document set entirely in Times New Roman and saved as a PDF carried six fonts:

• ✓, ★ and ☐ were set in Segoe UI Symbol.
• ✔ was set in Apple Color Emoji.
• The bullets of a list were set in Symbol.
• Calibri and Arial were carried for characters that do not show on the page.

That copy of Word used no Lucida. Which font fills in depends on the program, its version and the fonts on the computer, so the same document can carry a Lucida on another computer.

KDP's help lists four places a refused font can sit:

• any character, space or punctuation mark;
• a line break made while the font was active;
• headers and footers, even ones you cannot see;
• a style definition, even if no visible text uses the style.

Find where it is

Your PDF reader's document properties list the fonts a file carries, but not where each one is used.

The free PDF checker names each font KDP refuses, and what it sets on which page: for example, “LucidaGrande sets ✓ → on PDF p. 7.” When the font sets only spaces or line ends, it says so, since there is nothing to see on the page. The file is read in your browser and is not uploaded.

Replace it

1. Go to the page the checker names and select the characters. Set them in the font of your text. If that font does not have a character, replace the character with one it has, or with a word.
2. If the font sets only spaces or line ends, select the paragraph they are in and set it in the font of your text.
3. Check your styles. KDP's method for Word: open the Styles pane, look at each style's font, and modify every style that uses the refused font.
4. Export the PDF again and check it again before you upload it.

KDP lists two more methods. Selecting the whole document and setting one font comes last in its list: afterwards, every heading and every italic has to be set again by hand. Converting the text to outlines turns every letter into a shape, and KDP warns that it makes the file uneditable.

Another font error: faux bold and italic

The same help page describes a second font error. It appears when text is set in bold or italic and the file has no real bold or italic of that font. KDP's fix is to install the real bold or italic and export again with fonts embedded, or to remove the bold and italic. The PDF checker does not look for this one.

What we do

We set the text again in fonts we carry and use no font from your computer, so a Lucida in your Word file doesn't reach the PDF. On 6 November 2026 we set a manuscript with ✓, →, ★, ☐, ✔ and a bulleted list in it. Every character came out in a font the PDF carries, and none of them was a Lucida.

Sources

• KDP: Paperback Fonts
• KDP Community: Unsupported fonts message (5 August 2026)
• KDP Community: the unsupported Lucida problem (11 October 2026)