Fix a knowledge source that failed
Why a page, website or file can show Failed, what each reason means, and when Try again helps.
Updated October 24, 2026
See why it failed
On Knowledge, a failed source shows Failed and a See why link. Click it: the source's page shows the reason, then What you can do. Under Technical details you'll find the exact error, which is useful if you write to us.
A failed source teaches your agent nothing, but it still takes a slot in Sources used until you delete it.
Try again
For most reasons, the source's page shows a Try again button. Trying again never uses your plan's allowance.
For a website, each failed page has its own Try again next to Details. A whole website is tried again only when its scan found no page at all.
The reasons, and what to do
| What you see | What to do |
|---|---|
| The website took too long to respond. | Check that the site opens in your browser, then try again. |
| We couldn't connect to this website. | Check the address for typos and that the site is online, then try again. |
| The website returned an error. | This is usually temporary on the site's side. Try again later. |
| This page doesn't exist (error 404). | Open the address in your browser, then add the correct one. |
| The website refused access to this page. | Pages behind a login or closed to robots can't be read. Add the content as Q&A, or upload it as a file. |
| We couldn't find readable text on this page. | Some pages only show their text after JavaScript runs, which we can't read. Add the content as Q&A, or upload it as a PDF. |
| This address isn't a web page. | If it's a PDF or Word file, download it and upload it in the File tab. |
| This address is on a private or internal network. | Use the page's public address, the one your visitors see. |
| We couldn't find any pages to scan on this website. | The site may block robots or have no links we can follow. Add its key pages one by one. |
| Every page found is already in your knowledge base. | Nothing to do: those pages are already listed as sources. |
| This PDF is password-protected. | Remove the password and upload it again. |
| This file couldn't be read. | Open it on your computer, save a new copy and upload that. |
| The uploaded file wasn't saved correctly. | Upload the file again. |
| Processing stopped before it finished. | Try again. |
| Something went wrong while processing this source. | Try again. If it keeps failing, create a ticket or ask in Chat with us. |
When there's no Try again button, the source can't work as it is: fix the cause, delete the failed source, then add it again.
A file is Ready but the agent knows nothing from it
If a PDF's page says no text could be extracted, it's probably a scan: pictures of text. Use a PDF with selectable text, or add the content as Q&A.