I have a fairly large VB.NET WinForms project which loaded fine until recently. I have no recollection of any major changes in the startup code and I can only think of recent VS2019 upgrades that may have had an impact on the dev environment.
Here below is the Debug Output with the last line causing problem. Thanks in advance
'Soap.exe' (CLR v4.0.30319: DefaultDomain): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_64\mscorlib\v4.0_4.0.0.0__b77a5c561934e089\mscorlib.dll'. Symbols loaded. 'Soap.exe' (CLR v4.0.30319: DefaultDomain): Loaded 'C:\TWS API 976\samples\VB\soap_may3rd\soap\SoapCore\bin\Debug\Soap.exe'. Symbols loaded. 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\Microsoft.VisualBasic\v4.0_10.0.0.0__b03f5f7f11d50a3a\Microsoft.VisualBasic.dll'. Symbols loaded. 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System\v4.0_4.0.0.0__b77a5c561934e089\System.dll'. Symbols loaded. 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System.Core\v4.0_4.0.0.0__b77a5c561934e089\System.Core.dll'. Symbols loaded. 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System.Windows.Forms\v4.0_4.0.0.0__b77a5c561934e089\System.Windows.Forms.dll'. Symbols loaded. 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System.Drawing\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Drawing.dll'. Symbols loaded. 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System.Configuration\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Configuration.dll'. Symbols loaded. 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System.Xml\v4.0_4.0.0.0__b77a5c561934e089\System.Xml.dll'. Symbols loaded. 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System.Runtime.Remoting\v4.0_4.0.0.0__b77a5c561934e089\System.Runtime.Remoting.dll'. Symbols loaded. 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\TWS API 976\samples\VB\soap_may3rd\soap\SoapCore\bin\Debug\InteractiveBrokers.dll'. Symbols loaded. 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\Accessibility\v4.0_4.0.0.0__b03f5f7f11d50a3a\Accessibility.dll'. Symbols loaded. 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System.Windows.Forms.DataVisualization\v4.0_4.0.0.0__31bf3856ad364e35\System.Windows.Forms.DataVisualization.dll'. Symbols loaded. 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_MSIL\System.Management\v4.0_4.0.0.0__b03f5f7f11d50a3a\System.Management.dll'. Symbols loaded. The thread 0x176c has exited with code 0 (0x0). 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\TWS API 976\samples\VB\soap_may3rd\soap\SoapCore\bin\Debug\MathNet.Numerics.dll'. ReqCore done The thread 0x5ccc has exited with code 0 (0x0). 'Soap.exe' (CLR v4.0.30319: Soap.exe): Loaded 'C:\WINDOWS\assembly\GAC\Microsoft.mshtml\7.0.3300.0__b03f5f7f11d50a3a\Microsoft.mshtml.dll'. Module was built without symbols.