PDF Signature Shows a Question Mark
A yellow question mark on a signed PDF does not mean the signature is fake. It means the reader does not yet know whether to trust it, which is a different problem with an easy fix.
What the question mark is telling you
When a PDF reader opens a signed document it asks two separate questions. First, has this document been altered since it was signed? Second, do I trust the authority that issued the signing certificate?
A yellow question mark or a message about validity being unknown means the first answer was fine and the second is undecided. The reader can see a valid signature; it just has no basis yet for trusting the issuer. A red cross is a different matter entirely — that means the document was changed after signing, and that is worth taking seriously.
So in most cases nothing is wrong with your certificate or your document. The recipient's PDF reader simply has not been told to trust Indian certifying authorities, and the fix is on their side rather than yours.
How to make it verify
Update the reader's trusted certificate list
Adobe Acrobat Reader can fetch trusted root certificates automatically, and enabling that setting resolves most of these. Once the issuing authority is trusted, existing signed documents show as valid without re-signing anything.
Add the issuing authority to trusted identities manually
Where automatic updating is not available, the certifying authority's root certificate can be added to the reader's trusted list directly. Take it from the certifying authority itself, not from a third-party link.
Check you are opening it in a real PDF reader
Browser previews and phone viewers frequently do not validate signatures at all, and show a warning or nothing. Open the file in a proper reader before concluding anything is wrong.
If the recipient is a government department, ask what they expect
Some departments require a specific signature appearance or a timestamp. That is a requirement of how the document was signed, not a trust problem, and it needs fixing at the signing end.
A red cross is different — do not ignore it
That says the content changed after signing. Even something innocent like a page being re-saved by another tool breaks the signature. The document needs signing again on the final version.
Written 5 September 2026. Portals and browsers change; if something here no longer matches what you see, message us and we will tell you what changed.
Common questions
Still stuck? Send us the error
We fix these every week and we do not charge for a look. Send a screenshot of the exact error on WhatsApp along with your Windows version and browser. Most of these turn out to be a five-minute fix, and it is worth ruling that out before anyone sells you a new certificate.
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