How to Fix a NotebookLM Source That Will Not Load

Diagnose why a PDF, URL, or YouTube link fails to import into NotebookLM and apply the right workaround.

6 minBeginner

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Sometimes a source in NotebookLM gets stuck importing, shows an error, or comes in empty. Usually the cause is a scanned PDF, a blocked URL, or a file that is too large. This guide runs through the common failures and the fix for each.

What you need

The source that failed to import
A way to convert or re-export files (a PDF viewer or word processor)
A few minutes

Step 1: Identify the failure type

Look at what the source row shows. An error icon, a stuck spinner, or a source that imports but returns nothing each point to different causes. Note which one you are seeing.

NotebookLM - failed source

Sources

------------------------------

[ok] meeting-notes.txt

[!!] scanned-contract.pdf <- error

[..] https://example.com <- still loading

An error icon next to a source means the import did not complete.

Step 2: Match the symptom to a fix

Use the table below to jump to the right remedy. The most common culprit is a scanned PDF that has no selectable text layer for NotebookLM to read.

Symptom	Likely cause	Fix
PDF imports but chat finds nothing	Scanned image, no text layer	Run OCR, then re-upload
URL import fails	Site blocks crawling or needs login	Copy the text and paste it as a source
YouTube link rejected	No captions or private video	Use a public video with captions
Upload stalls	File too large	Split the file or export a lighter PDF

Step 3: OCR a scanned PDF

If your PDF is a scan, add a text layer with OCR before re-uploading. A free command-line tool like ocrmypdf does this in one step.

zsh - ocr

$ocrmypdf scanned-contract.pdf contract-ocr.pdf

Scanning contents... OCR done

Now upload contract-ocr.pdf into NotebookLM instead.

Step 4: Fall back to pasted text

When a URL refuses to import, open the page, select the article body, copy it, and use the Paste text source option. This bypasses any crawling restrictions because you are providing the content directly.

Check the source count limit

NotebookLM caps how many sources a notebook can hold. If new imports silently fail, you may be at the limit. Remove sources you no longer need, or combine several documents into one before uploading.

Result

After OCR or pasting the text, the source imports cleanly and the chat can cite it. Most NotebookLM loading problems trace back to scanned PDFs or blocked URLs, and both have quick workarounds.