I have across an issue in the installations, which was raised by many others in the previous posts.
Check the configuration of Internet Information Services (IIS)
Go to
Control Panel > Programs > Turn Windows features on or off
and make sure that WCF Services > HTTP Activation feature is installed for .NET Framework 4+,
whereas the components for .NET Framework 3.5 are switched off
All the boxed ticked are identical as per the instruction file
https://rapidscada.net/doc/content/latest/en/installation-and-run/software-installation.html
The only exception is mine is .NET 4.8 instead of .NET 4.6
Can you please assist, thanks.