Error message: "The root certificate in the Prism.exe signature cannot be verified."

When you try to launch Prism Windows, you may see one of two messages that prevent Prism from starting:

"The root certificate in the Prism.exe signature cannot be verified. To resolve this problem, go to microsoft.com"

The trusted root certificates on your system need to be updated. This is a Windows issue.

The first thing to do is run Windows Update and reboot. If that doesn't solve the problem, here are some places to learn more,

• From Microsoft: Support For Urgent Trusted Root Updates
• From Microsoft and very techy: Certificate Support and the Update Root Certificates Component
• From "The Windows Club":  Manage Trusted Root Certificates in Windows 10 / 8
• Also from The Windows Club, What are Root Certificates for Windows?

 "Prism cannot start"

In some cases, after the first error message is displayed, a second dialog will appear that states "You are using a version of Prism that has been illegally modified (hacked) to violate our license. To download the trial version or purchase Prism, go to https://graphpad.com/"

In this case, this message may (incorrectly) be displayed for the same reason as the first: the root certificates cannot be verified. The problem is that Prism's new anti-hacking features require verification of Prism's digital signature and this requires an up-to-date trusted root certificate on your system.

Following the instructions in the section above, updating the root certificates will fix the issue, and will cause both error messages to no longer be displayed.

If updating the root certificates does not fix the issue, check the Digital Signature Details of prism.exe. To do this, locate the folder where prism.exe file is located. By default, it is located in this folder: C:\Program Files\GraphPad\Prism 8

Right-click on the prism.exe file and choose Properties > Digital signatures. Select SHA256 certificate and click on Details button. Select View Certificate and view General and Certification Path tabs. They should look this way:

If you see no issues with a certificate in these dialogs, please send us a prism.exe file from your computer, so we can investigate further.