EV Code Signing (CSP Storage Provider Error)

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EV Code Signing (CSP Storage Provider Error)
 
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Andre Herrmann




Posts: 14
 Joined: 2022-11-05
Hello,

I’m suddenly encountering an error when performing EV code signing. This process used to work without any issues, but now it consistently fails with the following log entry:


<LogEntry Date="2025-10-21 09:25:57" Severity="Exception" Source="AddinExpress.Projects.Common.SignForm.LoadCertificateFromStore" ProcessId="40380">
<Exception Type="System.Security.Cryptography.CryptographicException" Source="AddinExpress.Projects.Common.SignForm.ValidateCertificate">
<Message>Only certificates using CSP Storage Provider are supported. </Message>
<StackTrace> at AddinExpress.Projects.Common.SignForm.ValidateCertificate(X509Certificate2 cert, String hashOrPath)
at AddinExpress.Projects.Common.SignForm.LoadCertificateFromStore(String hash)</StackTrace>
</Exception>
</LogEntry>


It seems the signing process now rejects my EV certificate with the message “Only certificates using CSP Storage Provider are supported.”

This is confusing because the same certificate and configuration worked fine before. I have signed several versions before and I haven’t changed anything in my signing setup or in the Add-in Express project configuration.

How I can restore compatibility or update my signing setup to work again?

Windows Version: 24H2 (26100.6899)
Addin Express Version: 10.2.4714.0

Also found this note from Microsoft but I'm not sure if it is related: https://learn.microsoft.com/en-us/windows/release-health/status-windows-11-24h2?utm_source=chatgpt.com#3697msgdesc

Thank you for your assistance!

Best regards,
Andre
Posted 21 Oct, 2025 07:43:41 Top
Andre Herrmann




Posts: 14
 Joined: 2022-11-05
Quick update:

The mentioned article above recommended to set the following registry entry to 0: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography\Calais\DisableCapiOverrideForRSA

That did indeed work for me.

Nevertheless, it would be great if you could investigate further and check if this is temporary or if it will be permanent and needs fixing in Add-in Express.

Best regards,
Andre
Posted 21 Oct, 2025 08:26:08 Top
Andrei Smolin


Add-in Express team


Posts: 19190
 Joined: 2006-05-11
Hello Andre,

Thank you for these details.

Regards from Poland (GMT+2),

Andrei Smolin
Add-in Express Team Leader
Posted 22 Oct, 2025 10:40:16 Top