I also go this message, after updating my certificate. A variety of messages - if I was able to build the installer it then failed to load giving me this message: "Exception reading message from file:///....vsto the manifest may not be valid or the file could not be opened" What the?? I've only updated the certificate!!! The detail of the error message included ... something about Manifest XML signature is no valid. Grrrr. 2 weeks later I resolved it by: Updating the .NET framework to 4.5 - previously my pre-requisite was 4.0 - on a Win7PC running Office 2007. I have clients running old versions - and need to make sure my software ok for them. Mike - the awesome support person at GlobalSign - also suggested updating the SDK and provided these references - I didn't need to try these in the end - but might as I haven't created an MSI (Windows Installer Package yet - only the Setup.exe) Hope this helps someone out there working to a deadline in the middle of the night! =============== Hello Suzy, I did a quick check on that message, I recall you are using a windows 7 environment last time and it been a while since you need to sign a new build. Can you make sure you have an updated SDK file? from a similar problem seems it was being caused by an old file. https://community.flexerasoftware.com/showthread.php?198574-Intermittent-digital-signature-extraction-issue You can download the latest version here. https://www.microsoft.com/en-ph/download/details.aspx?id=8279 Thanks Mike (GlobalSign) ... View more

I was also experiencing this issue when I recently had to update my certificate from GlobalSign. After many hours, I tried updating the .NET Framework in my addin - it had the pre-requisite 4.0 before; and I tried 4.5 This fixed my mystical issues. In the meantime the awesome Mike at GlobalSign found this post and gave me these updated links (I haven't tried updating the SDK - at the moment just desperately trying to get an updated version of my installer out to my new customers who are waiting). Hope one of these ideas helps someone else! Hello Suzy, I recall you are using a windows 7 environment last time and it been a while since you need to sign a new build. Can you make sure you have an updated SDK file? from a similar problem seems it was being caused by an old file. https://community.flexerasoftware.com/showthread.php?198574-Intermittent-digital-signature-extraction-issue You can download the latest version here. https://www.microsoft.com/en-ph/download/details.aspx?id=8279 Thanks Mike (GlobalSign) ... View more