Error when trying to sign an excel file with certificate

[MagnusNovak]

Hi everyone,

I've recently purchased a code signing certificate from Sectigo/Comodo but it's not working properly. I was able to generate the certificate and download it / install it on my computer (so it does appear as a valid certificate). However, when I try to sign any of my excel files, I get the following error message:

"Your signature could not be added to the document. If your signature requires a smart card, ensure that your card is installed correctly"

I'm using my personal computer so I don't have a smart card or anything of this type. Do you know where this issue could come from? I've tried multiple existing files and I was not able to sign any of them. However, when creating a blank excel file, I was able to sign it.

Appreciate any suggestion you may have!

Thanks

Edit: after a few tests, I found out something really weird: I can sign a blank spreadsheet but as soon as the workbook has a shape / picture with a hyperlink linking to a cell in a different tab, I get the error message. I don't know if this is the only scenario for which I have the error but it's definitely one of them. Unfortunately, the spreadsheets I'm trying to sign have plenty of pictures with hyperlink (used as menus)..