...

Summary

When starting the Performer Suite an error could occur.

Error

System.MissingMethodException: Method not found: '!!0[] System.Array.Empty()'. 

Cause

Your .NET Framework version is too low. It is needed to display the graphic interface of the Performer Suite.

Solution

Install .NET Framework 4.8 (4.8.1 is not recommended)

Download: https://dotnet.microsoft.com/en-us/download/dotnet-framework

Further information

Want to find out which .NET version you have installed?
https://docs.microsoft.com/en-us/dotnet/framework/migration-guide/how-to-determine-which-versions-are-installed