Fix Kindle Create Invalid Source Files: Clean DOCX for KDP

The moment this page is for

You finished the manuscript. Word opens it. Then Kindle Create (or KDP upload) stops you with Invalid Source Files / Invalid source file, or a close cousin: Corrupt file / Unsupported file format.

That is not a judgement on your writing. Amazon's own Kindle Create help treats “Invalid source file” as an import problem: try another version of the file; if Word opens it and Create still cannot, contact them. “Corrupt file” gets a concrete path—open in Word, Save As a new name as Word 97-2003 (.doc), then import again.

This page stays on that stuck moment. For the wider “preview looks wrong / TOC broken / fake headings” path, use the sister guide: Fix KDP Word Upload Issues.

Two different failures (do not mix them)

A) The file container is sick

Symptoms that usually mean the .docx itself is damaged or not a real Word file:

• Kindle Create: Invalid source file / Corrupt file / Unsupported file format.
• Filename longer than Amazon's limit, password-protected, empty, or full of special characters (Create's import table flags these).
• File lives only on a cloud drive, USB stick, or was renamed from another format to .docx.
• Word opens it with repair warnings, or Create fails while Word still “sort of” works.

Amazon's documented first moves (not affiliate):

1. Import a different version of the same manuscript if you have one.
2. Download a copy to the desktop (local disk), use a short simple filename, no password.
3. For corrupt: Word → Save As → new name → Word 97-2003 (*.doc) → import that (Kindle Create help).
4. Community cleanup many authors still use: Save as RTF → reopen → Save As a fresh .docx under a new name.
5. Confirm it is a real DOC/DOCX/PDF Create supports—not a renamed export.

If Create still cannot open a file Word opens cleanly, Amazon says to contact KDP support. Do that; do not keep re-uploading the same bytes.

B) The file opens, but the manuscript structure fights Kindle

Symptoms:

• Import eventually works, but preview/nav is wrong; or KDP's manuscript guide checklist fails (Track Changes on, print headers/footers/page numbers, tabs instead of styles, hard returns at every line end).
• Chapter titles are large bold text, not real Heading 1 / Markdown #.
• Title page, typed contents list, or cover image stuffed into the body upload.

That path is structure, not a “magic corrupt bit.” Rebuild body chapters with real headings, then generate a clean ebook-oriented DOCX. Details and checklist: Fix KDP Word Upload Issues.

What I do when Invalid Source shows up

I write and ship on KDP with the same constraints this tool encodes. Order I actually use:

1. Confirm the error text. Invalid / corrupt / unsupported / filename / password / empty → follow Amazon's matching row first (links below). Do not skip to a new tool while the file is still on OneDrive-only or password-locked.
2. Local fresh copy. Desktop folder, short name, no special characters.
3. Amazon corrupt path or RTF round-trip if Word can open it but Create cannot.
4. If the container is still unreliable, stop patching the sick file. Pull the body text into clean structure: Markdown # / ##, or Word Heading 1/2 only. Body chapters only—no title page, no hand-typed TOC, no cover image in this file. Optional bio as last chapter # About the Author.
5. Rebuild DOCX with the free Compiler at https://kdp.toolsforvip.com/ (≤15 MB; Author / optional Subtitle; Publisher defaults to Independently Published). Open the download once in desktop Word, confirm real headings and Track Changes off, then try Kindle Create or KDP again.
6. Preview in Kindle Previewer or KDP's online previewer before Publish.

The free Compiler does not “heal” every corrupted binary by magic. It is useful when you need a new, structured DOCX from text that already has real chapter markers. It will not replace proofreading, fix every Create edge case (tables/lists/footnotes Create cannot edit, password files, empty files), design a print interior (trim, gutters, bleed), or guarantee KDP approval.

Comparable facts (tool)

Soft note on the local Pack

Optional local Pack is only if you already need the same pipeline on your own machine often. Start with the free site. Soft listing when relevant: the optional Compiler Pack ($99) bundles companion tools—not a Kindle ebook, and not a substitute for KDP's own rules.

Official references (independent)

• Kindle Create — “Having trouble importing a file?” (Invalid source file, Corrupt file, filename, password, empty, unsupported): KDP help topic GUGQ4WDZ92F733GC
• Troubleshooting file conversion / corrupted source (do not rename formats pretending to be .docx): KDP help topic G202124410
• eBook manuscript formatting checklist: KDP help topic G200645680
• Paths to getting content on Kindle (includes Markdown → DOC(x) as a path): KDP help topic G79CTKR8BX79E96L

KDP Community threads on “Invalid Source Files” and corrupt Word uploads are useful for patterns; treat them as peer reports, not Amazon policy.

FAQ

Word opens the file. Why does Kindle Create still say Invalid source file?

Amazon's help says try another version; if Word opens it and Create cannot, contact them. Also rule out password, empty file, overlong or special-character filename, and cloud-only paths—Create's import table lists those separately.

Is Invalid Source the same as a bad Heading 1?

Not always. Invalid / corrupt / unsupported usually means the file Create cannot ingest. Fake headings and print baggage usually show up as preview/nav problems after import. Fix the container first; then clean structure.

Should I upload Markdown straight to KDP?

This workflow compiles Markdown or Heading-styled Word into a DOCX, then you use that DOCX (or Kindle Create → KPF) on KDP. Keep the upload file to body chapters.

Where is the tool?

https://kdp.toolsforvip.com/ — not /Compiler.

Does this guarantee approval?

No. Amazon still reviews files after upload.

Who makes this?

Lang Aijun. Free tool: https://kdp.toolsforvip.com/