Security Policy Errors

How to Fix Invalid Digital Signature Errors in an Access Database

Algirdas Jasaitis Oct 10, 2026 870 views

Question details

The user needs to resolve invalid or expired digital signature errors when opening an Access database project, and wants to learn how to update or install a new digital signature.

How to Fix Invalid Digital Signature Errors in an Access Database

Product: Microsoft Access
Device & OS: Windows
Scenario: Opening an existing Access database project on a new computer after its embedded digital signature has expired.
Observed behavior: The system displays security warnings regarding invalid or expired digital signatures, preventing macros and the database from running normally.

Before you start

Ensure you have administrative privileges on your Windows computer and verify that the Access database comes from a reliable source before modifying any Trust Center settings.

Solution 1Recommended

Move the Database to a Trusted Location

Quickly bypass the immediate security warning by placing the database file into a folder that Microsoft Access already trusts.

Adding a folder to your Trusted Locations list tells Access that any database within it is safe to run. This is the fastest way to resolve immediate signature warnings, provided you fully trust the file.

Open Trust Center Settings

Open Microsoft Access, click on 'File', select 'Options', and then navigate to the 'Trust Center' tab. Click the 'Trust Center Settings' button.

Access Trusted Locations

In the left pane of the Trust Center window, select 'Trusted Locations'.

Add a New Location

Click 'Add new location', browse to the folder where your database is stored, check the box to trust subfolders if needed, and click 'OK'.

Solution 2

Update or Install a New Digital Signature

Replace the expired digital signature with a valid certificate from a trusted authority or create a self-signed certificate.

Solution 3

Adjust Macro Security Settings

Modify your Trust Center settings to allow digitally signed macros to run while blocking unsigned ones.

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Frequently Asked Questions

Why did my Access database digital signature expire?

Digital certificates are issued with a specific validity period by the Certificate Authority. Once that time passes, the signature is marked as expired, which triggers security warnings when the database is opened on a new or existing computer.

Can I use the Office SelfCert tool to sign an Access database?

Yes, you can use the Office SelfCert utility to create a self-signed digital certificate for personal use. However, keep in mind that these certificates are not authenticated by a third-party authority and may not be trusted by other users on different computers.

Is it safe to bypass digital signature errors using Trusted Locations?

It is safe only if you are absolutely certain of the database's origin and trust its contents completely. Bypassing these security warnings for untrusted or downloaded files can expose your computer to malicious macros.

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