Certificate Error when Installing .NET Framework
When installing EHX v12 and v13 onto a Windows machine that does not have Windows Update configured or connected, EHX may fail to install .Net and ask for a manual install.
Check that the Windows machine is running Windows 7 SP 1 as a minimum, and manually install the following patches, then restart the machine, and install the Microsoft .Net 4.8 offline installer:
Install SHA-2 Code Signing Support Updates
As explained in this Microsoft article, you need to enable SHA-2 Code signing support by installing the following updates:
Microsoft .NET Framework 4.8 offline installer for Windows - Microsoft Support