Fix "Signature validity unknown"
Verify the digital signature on your signed PDF and download a copy with the green verified tick, ready to print.
About Fix "Signature validity unknown"
Your signed PDF carries a digital signature, but Adobe Reader often shows a yellow question mark and "Signature validity is unknown". That usually does not mean anything is wrong — Adobe simply does not trust India's signing authorities by default.
- Select your files
- Press “Download verified PDF”
- Download
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More about Fix "Signature validity unknown"
Upload the PDF here: the signature is checked against India's CCA roots, you see who signed it, when, and whether the file is unchanged, and you get the certificate plus the exact steps to show the green tick in Adobe.
Tips
- Use the original signed file you downloaded — a re-saved or compressed copy loses its signature.
- In Adobe, trust the certificate once and every document from the same authority shows the green tick.
Also called: सिग्नेचर वैलिडिटी अननोन ठीक करें · "সিগনেচার ভ্যালিডিটি আননোন" ঠিক করুন
FAQ
Is the question mark a problem?
Usually not. It means Adobe could not confirm the signer, not that the document is fake. This page confirms it.
Will you change my PDF?
No — the file is only checked. Changing it would break the signature.
Is Fix "Signature validity unknown" free?
Yes. Fix "Signature validity unknown" is completely free with no signup, no watermark and no daily limit for normal use (a fair-use limit protects the server from abuse).
Is it safe to use Fix "Signature validity unknown"?
Yes. Files are sent over HTTPS, processed on our own server and deleted automatically — immediately after processing and in any case within 1 hour.
Which files can I use?
PDF — you can select several files at once.
Does it work on mobile?
Yes. Every tool is designed for phones first and works in any modern mobile browser on Android and iPhone.