PDF Printing Issues

Fix Acrobat Reader Invalid Certificate Error When Printing PDFs

Camila Milosovich Oct 19, 2026 868 views

Question details

The user is unable to print a PDF document because the application blocks the process due to an invalid certificate error.

How to Fix Acrobat Reader Invalid Certificate Error When Printing PDFs

Product: Adobe Acrobat Reader
Device & OS: Honor 90 (Android)
Scenario: Attempting to print a digitally signed PDF document to a Canon G5010 printer using a mobile device.
Observed behavior: Acrobat Reader blocks the print job and displays the error message, 'Printing was blocked because the certificate is not valid.'

Before you start

Ensure your mobile device and printer are connected to the same network, and verify whether the PDF document was digitally signed by you or received from someone else.

Solution 1Recommended

Re-sign the PDF and Update Acrobat Reader

If you signed the document yourself, the existing certificate may be corrupted or outdated. Generating a fresh copy and updating your app often resolves the error.

Digital certificates can occasionally expire or become unrecognized by newer security standards. Updating the Acrobat Reader application ensures that the latest root certificates and security patches are applied on your device.

Obtain an unsigned copy

Locate and obtain a fresh, completely unsigned copy of the original PDF document before any digital signatures were applied.

Update Acrobat Reader

Open the Google Play Store on your phone, search for 'Adobe Acrobat Reader', and tap 'Update' to install the latest version.

Restart your device

Restart your phone to ensure the app update and background security services are fully refreshed.

Re-sign and print

Open the unsigned PDF in the newly updated Acrobat Reader, digitally sign the document again, and attempt to print it to your Canon printer.

Requesting a New Document: If you are not the original signer of the document, you must contact the sender and ask them to verify their certificate or provide a fresh, cleanly signed copy.

Solution 2

Verify Device and Printer Certificates

Sometimes the invalid certificate error is caused by outdated security protocols or system certificates on your mobile device or printer.

Print and Sign PDFs Seamlessly with WPS Office

Avoid restrictive certificate validation errors by using WPS Office to open, view, sign, and print your PDF documents effortlessly directly from your mobile device.

1. Install WPS Office: Download and install the free WPS Office app from the Google Play Store.
2. Open your PDF: Launch WPS Office, tap on 'Files', and open the PDF document you wish to print.
3. Print the document: Tap on the 'Tools' icon at the bottom, navigate to the 'File' tab, select 'Print', choose your connected printer, and confirm the print job.

Easily print PDFs without encountering complex certificate validation blocks.Fully compatible with standard Adobe PDF formats and Microsoft Office documents.Add secure digital signatures and annotations directly on your mobile device.Lightweight, fast, and completely free to download on Android.

microsoft office alternative - wps office

Frequently Asked Questions

Why does Acrobat Reader say 'Printing was blocked because the certificate is not valid'?

This error occurs when the digital signature on the PDF has expired, is corrupted, or uses a certificate authority that your device or app version no longer trusts. It serves as a security measure to prevent printing potentially altered or unverified documents.

Can I print a PDF that has an invalid certificate without signing it again?

In most cases, Adobe restricts printing for security reasons if the certificate is deemed invalid. You will either need to obtain an unsigned version of the document or use an alternative PDF reader, such as WPS Office, to bypass the app-specific security restriction.

How do I check for Acrobat Reader updates on my Android phone?

Open the Google Play Store app, tap your profile icon in the top right corner, select 'Manage apps & device', and look for pending updates. If Adobe Acrobat Reader is listed, tap 'Update' next to it.

PDF Troubleshooting