No Trusted Publisher Option for VSTO for Excel

[Gina]

I'm trying to install a VSTO add-in that I created with AI Enterprise. The add-in won't finish installing, but gives the message:

"The solution can not be installed because it is signed by a publisher whom you have not yet chosen to trust. If you trust the publisher, add the certificate to the Trusted Publisher list."

Upon installation, it never gives the user the option to trust the publisher; it just gives this error, and the user has to close the error window to proceed. How can I give the user to option to trust the publisher, or even make the problem not occur?

In AI, I have selected "Enable signing" in the Digital Signature tab. And I've tried both (1) selecting a certificate from system store, and (2) selecting "most suited certificate." These are certificates created inside Visual Studio under the "Signing" tab.

[Dan]

Hello Gina,

Please keep in mind that to sign your deployment, you must have a code-signing certificate from a root certificate authority.
You can take a look on our Why does the "Unknown Publisher" message appear during the install of a digitally signed package? FAQ's article and on the How to: Create Your Own Test Certificate article which may be useful to you.

Please let us know if that helped.

Best regards,
Dan

[Gina]

Dan, When I attach the certificate I purchased from Verisign (Symantec) on the "Digital Signature" tab in my AI Enterprise project, and then install the program on a user's computer, the installation seems to run fine. However, when I open Excel, I get the message in the attached .jpg file.

Do I have to manually install the certificate on each end user's machine, or is the AI installation package supposed to do this? In examples on the internet, people typically get an option to accept the publisher. Mine doesn't give this.

Error Msg.JPG (94.8 KiB) Viewed 13579 times

[Dan]

Hi Gina,

I'm not sure why you encountered this behavior. Can you please try to manually sign all your office addin files and manually install them and see if the behavior still persist?

Happy Holidays,
Dan

[AdiKonstantin]

hello,

Please follow the below steps and see what are your settings:
1. File
2. Options
3. trust Center
4. Trust Center Settings...
5. Add-ins

In this page you should have unchecked the inconvenient items (in my case the first one was the one blocking my AddIn to be loaded in customers' Excel clients)

Adi

[Daniel]

Hello Adi and welcome to our forums,

Thank you for your feedback on this issue. Certainly this will be useful for future users facing similar error.

All the best,
Daniel