DLL Management
In some scenario, Windows may experience issues with the DLL file that provides RTD functionality in Excel. If “#N/A” is displayed in all cells of an Excel sheet, the first step to resolve the issue is to reregister the DLL.
- TWSAPI must be installed using Admin rights. This allows required dlls (CSharpAPI.dll and TwsRtdServer.dll) to be correctly registered in Windows system registry and Excel will find it.
- Optional: to manually unregister dll run the following (using Admin rights):
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\RegAsm.exe /unregister "C:\TWS API\source\CSharpClient\TwsRtdServer\bin\Release\TwsRtdServer.dll" - Optional: to manually register dll run the following (using Admin rights):
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\RegAsm.exe /codebase "C:\TWS API\source\CSharpClient\TwsRtdServer\bin\Release\TwsRtdServer.dll"
- Optional: to manually unregister dll run the following (using Admin rights):
- Open “Excel > File > Options > Excel Options > Trust Center > Trust Center Settings”
- Make sure that :
- “Add-ins -> Require Application Add-ins to be signed by Trusted Publisher” is NOT selected
- “Add-ins -> Disable all Application Add-ins” is NOT selected
- After settings were changed, Excel must be restarted

