Activation failure: ConfigurationErrorsException

Windows 11, 3.1.5.1, installing Scrivener on recently purchased new computer.

The License manager ended unexpectedly. Please, install .NET v4.6.2 or higher, install the latest critical and recommended Windows Updates and try again.

Log: 
Unhandled Exception: System.TypeInitializationException: The type initializer for 'System.Net.ServicePointManager' threw an exception. ---> System.TypeInitializationException: The type initializer for 'System.Net.ComNetOS' threw an exception. ---> System.Configuration.ConfigurationErrorsException: Configuration system failed to initialize ---> System.Configuration.ConfigurationErrorsException: Unrecognized configuration section startup. (C:\Program Files\Scrivener3\paddle\Paddle.exe.Config line 3)
   at System.Configuration.ConfigurationSchemaErrors.ThrowIfErrors(Boolean ignoreLocal)
   at System.Configuration.BaseConfigurationRecord.ThrowIfParseErrors(ConfigurationSchemaErrors schemaErrors)
   at System.Configuration.ClientConfigurationSystem.EnsureInit(String configKey)
   --- End of inner exception stack trace ---
   at System.Configuration.ClientConfigurationSystem.EnsureInit(String configKey)
   at System.Configuration.ClientConfigurationSystem.PrepareClientConfigSystem(String sectionName)
   at System.Configuration.ClientConfigurationSystem.System.Configuration.Internal.IInternalConfigSystem.GetSection(String sectionName)
   at System.Configuration.ConfigurationManager.GetSection(String sectionName)
   at System.Configuration.PrivilegedConfigurationManager.GetSection(String sectionName)
   at System.Diagnostics.DiagnosticsConfiguration.GetConfigSection()
   at System.Diagnostics.DiagnosticsConfiguration.Initialize()
   at System.Diagnostics.DiagnosticsConfiguration.get_Sources()
   at System.Diagnostics.TraceSource.Initialize()
   at System.Net.Logging.InitializeLogging()
   at System.Net.Logging.get_On()
   at System.Net.ComNetOS..cctor()
   --- End of inner exception stack trace ---
   at System.Net.ServicePointManager..cctor()
   --- End of inner exception stack trace ---
   at System.Net.ServicePointManager.EnsureConfigurationLoaded()
   at ScrPaddle.Program.Main(String[] args)